Electrically and magnetically enhanced ionized physical vapor deposition unbalanced sputtering source

ABSTRACT

A method of depositing a layer on a substrate includes applying a first magnetic field to a cathode target, electrically coupling the cathode target to a first high power pulse resonance alternating current (AC) power supply, positioning an additional cylindrical cathode target electrode around the cathode, applying a second magnetic field to the additional cylindrical cathode target electrode, electrically coupling the additional cylindrical cathode target electrode to a second high power pulse resonance AC power supply, generating magnetic coupling between the cathode target and an anode, providing a feed gas, and selecting a time shift between negative voltage peaks associated with AC voltage waveforms generated by the first high power pulse resonance AC power supply and the second high power pulse resonance AC power supply. An apparatus includes a vacuum chamber, cathode target magnet assembly, first high power pulse resonance AC power supply, additional electrode, additional electrode magnet assembly, second high power pulse resonance AC power supply, and feed gas.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S.application Ser. No. 16/025,928, filed Jul. 2, 2018, which is acontinuation-in-part application of International Application No.PCT/US17/48438, filed Aug. 24, 2017, which claims the benefit of U.S.Provisional Application No. 62/482,993, filed Apr. 7, 2017, thedisclosures of which are incorporated by reference herein in theirentireties.

U.S. application Ser. No. 15/260,841, filed Sep. 9, 2016 entitled“Capacitive Coupled Plasma Source for Sputtering and Resputtering”, U.S.application Ser. No. 15/261,119, filed Sep. 9, 2016 entitled“Magnetically Enhanced High Density Plasma-Chemical Vapor DepositionPlasma Source for Depositing Diamond and Diamond-Like Films”, and U.S.application Ser. No. 15/261,197, filed Sep. 9, 2016 entitled“Magnetically Enhanced Low Temperature-High Density Plasma-ChemicalVapor Deposition Plasma Source for Depositing Diamond and Diamond LikeFilms” are incorporated herein by reference in their entireties.

This application is a continuation-in-part application of U.S.application Ser. No. 15/260,857, filed Sep. 9, 2016, which claims thebenefit of U.S. Provisional Application No. 62/270,356, filed Dec. 21,2015, the disclosures of which are incorporated herein by reference intheir entireties.

BACKGROUND Field

The disclosed embodiments generally relate to an ionized physical vapordeposition (I-PVD) apparatus and method for sputtering target materialon a surface of a substrate. In particular, the disclosed embodimentsrelate to an apparatus and method of generating high density capacitivecoupled plasma (CCP) for sputtering applications in addition to acathode sputtering target discharge. The disclosed embodiments alsorelate to electrically and magnetically enhanced unbalanced magnetronand non-magnetron sputtering apparatuses and methods.

Related Art

An ionized physical vapor deposition (I-PVD) sputtering and resputteringprocess can be performed in the same process module in the presence ofan additional inductively coupled plasma (ICP) source. An example ofsuch an apparatus and process is described in U.S. Publication No.2008/0190760A1, which is incorporated herein by reference in itsentirety. The I-PVD sputtering source is a magnetron sputtering source,in which magnetic field lines terminate on a target surface. Theresputtering process, which is sputter etching, can be performed withargon gas ions or sputtered copper ions. In order to increase ionizationof the gas and sputtered material ions, an ICP coil is positioned in avacuum chamber between a magnetron sputtering source and a substrate.

SUMMARY

The disclosed embodiments relate to an electrically and magneticallyenhanced I-PVD unbalanced magnetron and non-magnetron apparatus andmethod for sputtering. Magnetic field geometry of the electrically andmagnetically enhanced unbalanced magnetron sputtering source has anunbalanced magnetron configuration on a cathode target surface. Magneticfield lines that form a magnetron configuration on the cathode targetsurface are unbalanced from the center. In some embodiments, magneticfield lines are unbalanced from the edges. The unbalanced magnetic fieldlines are terminated on a magnet assembly positioned inside anadditional electrode that is electrically isolated from ground andpositioned around the cathode target. The additional electrode isconnected to a power supply that can generate a positive, negative, orhigh frequency bipolar voltage with a frequency in the range of 100 KHzto 100 MHz. In some embodiments, the additional electrode is connectedto the power supply that generates an RF voltage. In some embodiments,the additional electrode can be made from cathode target material. Insome embodiments, the additional electrode is not connected to a powersupply and has a floating potential. In some embodiments, at least aportion of the magnetic field lines passing the gap are positionedadjacent to the additional electrode prior to terminating on themagnets. The gap can be formed between the anode and additional to acathode target gap cathode. The gap cathode can be connected with an RFpower supply. The RF power supply can generate voltage oscillations witha frequency are in the range of 100 kHz to 100 MHz. The gap cathode canbe grounded through an inductor to eliminate negative voltage biasgenerated by RF discharge. In some embodiments, magnetic field geometryof the electrically and magnetically enhanced sputtering source does notform a magnetron configuration on a cathode target surface. In thiscase, magnetic field lines on the cathode target surface aresubstantially perpendicular to the cathode target surface. In someembodiments, the additional electrode magnet assembly forms a cuspmagnetic field. In some embodiments, the additional electrode magnetassembly forms a cusp magnetic field in the gap.

The electrically and magnetically enhanced I-PVD unbalanced sputteringsource according to the disclosed embodiments includes a cathode targetassembly connected to the power supply, an additional electrode assemblyelectrically isolated from ground, a power supply connected to theadditional electrode assembly, a first additional electrode magnetassembly magnetically coupling the additional electrode assembly and thecathode target, a stationary or rotating cathode magnet assembly thatgenerates an unbalanced magnetron magnetic field configuration on thetarget surface, an anode that is connected to ground, and a flowingliquid that cools and controls the temperature of the cathode.

The magnetically and electrically enhanced I-PVD unbalanced sputteringsource may include: a second additional electrode magnet assembly, anelectrical circuit that has at least one inductor connected between anadditional electrode and ground, and an electrical circuit that has atleast one inductor connected between a cathode target assembly andground, as well as a gap that has a gap cathode and is positioned aroundthe additional electrode.

The electrically and magnetically enhanced I-PVD unbalanced magnetronsputtering apparatus includes an electrically and magnetically enhancedI-PVD unbalanced magnetron sputtering source, vacuum chamber, substrateholder, substrate, feed gas mass flow controller, and vacuum pump.

The electrically and magnetically enhanced I-PVD unbalanced magnetronsputtering apparatus may include a substrate heater, controller,computer, feed gas activation source, substrate bias power supply, andan additional electrically and magnetically enhanced I-PVD unbalancedmagnetron sputtering source.

A method of providing electrically and magnetically enhanced I-PVDunbalanced magnetron sputtering includes positioning an electrically andmagnetically enhanced I-PVD unbalanced magnetron sputtering sourceinside a vacuum chamber, positioning a substrate on the substrateholder, applying electrical potential to the additional electrodeassembly, providing feed gas, applying power between the cathode targetand the anode to form a plasma, and depositing a layer of targetmaterial on the substrate surface.

A method of providing electrically and magnetically enhanced sputteringmay include applying power to the substrate holder to generate substratebias, attracting positive ions from sputtered target material atoms tothe substrate, applying heat to the substrate, and flowing feed gasthrough a gas activation source.

A method of depositing a layer on a substrate includes applying amagnetic field to a cathode target to generate an unbalanced magneticfield and a magnetron configuration on the cathode target; electricallycoupling an additional electrode to a ground electrical potential usingan electrical circuit comprising an inductor; electrically coupling theadditional electrode to a radio frequency (RF) power supply; generatingmagnetic coupling between the cathode target and the anode; providing afeed gas; and applying power to the cathode target, wherein the RF powersupply provides a power selected to increase ionization of sputteredtarget material atoms associated with the cathode target duringsputtering.

The method may include coupling a DC power supply to the cathode,wherein the DC power supply provides output power in a range of 1 to 100kW. The feed gas may include a noble gas including at least one ofargon, xenon, neon, and krypton. The feed gas may include a mixture of anoble gas and a reactive gas. The method may include coupling the RFpower supply to the cathode target, wherein the RF power supply providesoutput power in a range of 1 to 20 kW; and coupling a substrate biasvoltage to a substrate holder, wherein the substrate bias voltagecomprising a range of −10 V to −200 V. The feed gas may include amixture of a noble gas and a reactive gas; and a mixture of a noble gasand a gas that comprises atoms of the cathode target material. Themethod may include coupling a pulsed DC power supply to the cathodetarget, wherein the pulsed DC power supply provides an output peak powerduring a pulse in a range of 10 to 1000 kW.

An electrically and magnetically enhanced ionized physical vapordeposition (I-PVD) unbalanced sputtering apparatus that deposits a layeron a substrate includes a vacuum chamber; a cathode target magnetassembly that generates an unbalanced magnetic field and provides amagnetron configuration on a target surface; an additional electrodecoupled to a ground electrical potential using an electrical circuitcomprising an inductor, wherein the anode is coupled to a radiofrequency (RF) power supply; an additional electrode magnet assemblythat generates magnetic coupling between a cathode target and theadditional electrode; a feed gas; a power supply coupled to the cathodemagnet target assembly, wherein the power supply generates a magnetrondischarge, and the RF power supply provides a power selected to increasean ionization of atoms associated with the cathode target duringsputtering.

The power supply coupled to the cathode target assembly may include a DCpower supply providing output power in a range of 1 to 100 kW. The powersupply coupled to the cathode target assembly may include a pulsed powersupply providing a target power density during a pulse in a range of 0.1to 5 kW/cm2. A pulsed power supply may generate bipolar asymmetricalvoltage oscillations. The amplitude of the negative oscillations can bein the range of 500 V to 3000 V. The amplitude of positive oscillationscan be in the range of 50 V to 500 V. The duration of the voltageoscillations can be in the range of 5 μs to 50 μs. The frequency ofthese oscillations can be in the range of 10 kHz to 200 kHz. Theapparatus may include a substrate bias power supply coupled to asubstrate holder, wherein the substrate bias power supply provides abias voltage on a substrate in a range of −10 to −200 V. The feed gasmay include a noble gas that includes at least one of argon, xenon,neon, and krypton; and/or a mixture of a noble gas and a reactive gas.Reactive gas can be N₂, O₂ and H₂. The power supply coupled to thecathode magnet target assembly may include a RF power supply providingoutput power in a range of 1 to 20 kW. The power supply coupled to thecathode magnet target assembly may include a pulsed RF power supplyproviding output power during the pulse in a range of 5 to 50 kW. Thefeed gas may include a mixture of a noble gas and gas that comprisesatoms of the cathode target. The cathode magnet target assembly mayrotate with a speed in a range of 10 to 100 revolutions per minute.

The disclosed embodiments relate to a high energy density plasma (HEDP)magnetically enhanced sputtering source, apparatus, and method forsputtering hard coatings in the presence of high-power pulseasymmetrical alternating current (AC) waveforms. The high power pulseasymmetric AC waveform is generated by having a regulated voltage sourcewith variable power feeding a regulated voltage to the high power pulsesupply with programmable pulse voltage duration and pulse voltagefrequency that produces, at its output, a train of regulated amplitudeunipolar negative voltage pulses with programmed pulse frequency andduration, and supplying these pulses to a tunable pulse forming network(PFN) including a plurality of inductors and capacitors for pulseapplications connected in a specific format coupled to a magneticallyenhanced sputtering source. By adjusting the pulse voltage amplitude,duration, and frequency of the unipolar negative voltage pulses andtuning the values of the inductors and capacitors in the PFN coupled toa magnetically enhanced sputtering source, a resonance pulsed asymmetricAC discharge is achieved.

Another method to produce a resonance pulsed asymmetric AC discharge isimplemented using a fixed unipolar pulse power supply parameters(amplitude, frequency, and duration) feeding a pulse forming network, inwhich the numerical values of the inductors and capacitors, as well asthe configuration can be tuned to achieve the desired resonance valueson the HEDP source to form a layer on the substrate. The tuning of thePFN can be done manually with test equipment, such as an oscilloscope,voltmeter, and current meter, or other analytical equipment; orelectronically with a built-in software algorithm, variable inductors,variable capacitors, and data acquisition circuitry. The negativevoltage from the pulse asymmetric AC waveform generates high densityplasma from feed gas atoms and sputtered target material atoms betweenthe cathode sputtering target and the anode of the magnetically enhancedsputtering source. The positive voltage from the pulse asymmetrical ACwaveform attracts plasma electrons to the cathode sputtering area andgenerates positive plasma potential. The positive plasma potentialaccelerates gas and sputtered target material ions from the cathodesputtering target area towards the substrate that improve depositionrate and ion bombardment on the substrate. The reverse electron currentcan be up to 50% from the discharge current during a negative voltage.

In some embodiments, the magnetically enhanced sputtering source is ahollow cathode magnetron. The hollow cathode magnetron includes a hollowcathode sputtering target, and the tunable PFN has a plurality ofcapacitors and inductors. The resonance mode associated with the tunablePFN is a function of the input unipolar voltage pulse amplitude,duration, and frequency generated by the high power pulse power supply,inductance, resistance, and capacitance of the hollow cathode magnetron,or any other magnetically enhanced device; the inductance, capacitance,and resistance of the cables between the tunable PFN and hollow cathodemagnetron; and a plasma impedance of the hollow cathode magnetronsputtering source itself as well as the sputtered material.

In some embodiments, rather than the hollow cathode magnetron, acylindrical magnetron is connected to an output of the tunable PFN. Insome embodiments, rather than the hollow cathode magnetron, a magnetronwith flat target is connected to the output of the tunable PFN. In theresonance mode, the output negative voltage amplitude of the high powerpulse voltage mode asymmetrical AC waveform on the magnetically enhanceddevice exceeds the negative voltage amplitude of the input unipolarvoltage pulses into the tunable PFN by 1.1-5 times. The unipolarnegative high power voltage output can be in the range of 400V-5000V. Inthe resonance mode, the absolute value of the negative voltage amplitudeof the asymmetrical AC waveform can be in the range of 750-10000 V. Inthe resonance mode, the output positive voltage amplitude of theasymmetrical AC waveform can be in the range of 100-5000 V. In somecases, the resonance mode of the negative voltage amplitude of theoutput AC waveform can reach a maximum absolute value while holding allother component parameters (such as the pulse generator output, PFNvalues, cables and HEDP source) constant, wherein a further increase ofthe input voltage to the tunable PFN does not result in a voltageamplitude increase on the HEDP source, but rather an increase in theduration of the negative pulse in the asymmetric AC waveform on the HEDPsource.

Sputtering processes are performed with a magnetically and electricallyenhanced HEDP plasma source positioned in a vacuum chamber. As mentionedabove, the plasma source can be any magnetically enhanced sputteringsource with a different shape of sputtering cathode target. Magneticenhancement can be performed with electromagnets, permanent magnets,stationary magnets, moveable magnets, and/or rotatable magnets. In thecase of a magnetron sputtering source, the magnetic field can bebalanced or unbalanced. A typical power density of the HEDP sputteringprocess during a negative portion of the high voltage AC waveform is inthe range of 0.1-20 kW/cm′. A typical discharge current density of theHEDP sputtering process during a negative portion of the high voltage ACwaveform is in the range of 0.1-20 A/cm². In the case of the hollowcathode magnetron sputtering source, the magnetic field lines form amagnetron configuration on a bottom surface of the hollow cathode targetfrom the hollow cathode magnetron. Magnetic field lines aresubstantially parallel to the bottom surface of the hollow cathodetarget and partially terminate on the bottom surface and side walls ofthe hollow cathode target. The height of the side walls can be in therange of 5-100 mm. Due to the presence of side walls on the hollowcathode target, electron confinement is significantly improved whencompared with a flat target in accordance with the disclosedembodiments. In some embodiments, an additional magnet assembly ispositioned around the walls of the hollow cathode target. In someembodiments, there is a magnetic coupling between additional magnets anda magnetic field forms a magnetron configuration.

Since the high power resonance asymmetric AC waveform can generate HEDPplasma and, therefore, significant power on the magnetically enhancedsputtering source, the AC waveform is pulsed in programmable bursts toprevent damage to the magnetically enhanced sputtering source fromexcess average power. The programmable duration of the AC pulse burstscan be in the range of 0.1-100 ms. The frequency of the programmable ACpulse bursts can be in the range of 1 Hz-10000 Hz. In some embodiments,the AC waveform is continuous or has a 100% duty cycle assuming the HEDPplasma source can handle the average power. The frequency of the pulsedAC waveform inside the programmable pulse bursts can be programmed inthe range of 100 Hz-400 kHz with a single frequency or mixed frequency.

The magnetically enhanced HEDP sputtering source includes a magnetronwith a sputtering cathode target, an anode, a magnet assembly, aregulated voltage source connected to a high power pulsed power supplywith programmable output pulse voltage amplitude, frequency, andduration. The pulsed power supply is connected to the input of thetunable PFN, and the output of the tunable PFN is connected to thesputtering cathode target on the magnetically enhanced sputteringsource. The tunable PFN, in resonance mode, generates the high powerresonance asymmetrical AC waveform and provides HEDP on the magneticallyenhanced sputtering source.

The magnetically enhanced high power pulse resonance asymmetric AC HEDPsputtering source may include a hollow cathode magnetron with a hollowcathode sputtering target, a second magnet assembly positioned aroundthe side walls of the hollow cathode target, an electrical switchpositioned between the tunable PFN and hollow cathode magnetron with aflat sputtering target rather than a hollow cathode shape, and amagnetic array with permanent magnets, electromagnets, or a combinationthereof.

The magnetically enhanced high power pulse resonance asymmetric AC HEDPsputtering apparatus includes a magnetically enhanced HEDP sputteringsource, a vacuum chamber, a substrate holder, a substrate, a feed gasmass flow controller, and a vacuum pump.

The magnetically enhanced high power pulse resonance asymmetric AC HEDPsputtering apparatus may include one or more electrically andmagnetically enhanced HEDP sputtering sources, substrate heater,controller, computer, gas activation source, substrate bias powersupply, matching network, electrical switch positioned between thetunable PFN and magnetically enhanced HEDP sputtering source, and aplurality of electrical switches connected with a plurality ofmagnetically enhanced high power pulse resonance asymmetric AC HEDPsputtering sources and output of the tunable PFN.

A method of providing high power pulse resonance asymmetric AC HEDP filmsputtering includes positioning a magnetically enhanced sputteringsource inside a vacuum chamber; connecting the cathode target to theoutput of the tunable PFN that, in resonance mode, generates the highpower asymmetrical AC waveform; positioning a substrate on a substrateholder; providing feed gas; programing voltage pulse frequency andduration; adjusting pulse voltage amplitude of the programmed voltagepulses with fixed frequency and duration; feeding the tunable PFN; andgenerating the output high voltage asymmetrical AC waveform with anegative voltage amplitude that exceeds the negative voltage amplitudeof the voltage pulses in the resonance mode, thereby resulting in a highpower pulse resonance asymmetric AC HEDP discharge.

The method of magnetically enhanced high power pulse resonanceasymmetric AC HEDP film sputtering may include positioning an electricalswitch between the hollow cathode magnetron and the tunable PFN that, inresonance mode, generates the high voltage asymmetrical AC waveform;applying heat to the substrate or cooling down the substrate; applyingdirect current (DC) or radio frequency (RF) continuously and/or using apulse bias voltage to the substrate holder to generate a substrate bias;connecting the tunable PFN that, in resonance mode, generates the highvoltage asymmetrical AC waveform simultaneously to the plurality ofhollow cathode magnetrons or magnetrons with flat targets; and ignitingand sustaining simultaneously HEDP in the plurality of the hollowcathode magnetron.

The disclosed embodiments include a method of sputtering a layer on asubstrate using a high power pulse resonance asymmetric AC HEDPmagnetron. The method includes configuring an anode and a cathode targetmagnet assembly to be positioned in a vacuum chamber with a sputteringcathode target and the substrate; applying high power negative unipolarvoltage pulses with regulated amplitude and programmable duration andfrequency to a tunable PFN, wherein the tunable PFN includes a pluralityof inductors and capacitors; and adjusting an amplitude associated withthe unipolar voltage pulses with programmed duration and frequency tocause a resonance mode associated with the tunable pulse forming networkto produce an output high power pulse resonance asymmetric AC on theHEDP sputtering source. The output AC waveform from the tunable PFN isoperatively coupled to the HEDP sputtering cathode target, and theoutput high power pulse resonance asymmetric AC waveform includes anegative voltage exceeding the amplitude of the input unipolar voltagepulses to the tunable PFN during the resonance mode and sputteringdischarge of the HEDP magnetron. With all conditions fixed, any furtherincrease of the amplitude of the unipolar voltage pulses causes only anincrease in the duration of the maximum value of the negative voltageamplitude of the output high power asymmetric AC waveform in response tothe pulse forming network being in the resonance mode, thereby causingthe HEDP magnetron sputtering discharge to form the layer on thesubstrate.

The disclosed embodiments further include an apparatus that sputters alayer on a substrate using a high-power pulse resonance asymmetric ACHEDP magnetron. The apparatus includes an anode, cathode target magnetassembly, regulated high voltage source with variable power, high powerpulse power supply with programmable voltage pulse duration andfrequency power supply, and a tunable PFN. The anode and cathode targetmagnet assembly are configured to be positioned in a vacuum chamber witha sputtering cathode target and the substrate. The high power pulsepower supply generates programmable unipolar negative voltage pulseswith defined amplitude, frequency, and duration. The tunable pulseforming network includes a plurality of inductors and capacitors, andthe amplitude of the voltage pulses is adjusted to be in the resonancemode associated with the tunable PFN and magnetically enhancedsputtering source for specific programmed pulse parameters, such asamplitude, frequency, and duration of the unipolar voltage pulses. Theoutput of the tunable PFN is operatively coupled to the sputteringcathode target, and the output of the tunable PFN in the resonance modegenerates a high power resonance asymmetric AC waveform that includes anegative voltage exceeding the amplitude of the input to tunable PFNunipolar voltage pulses. An AC waveform sustains plasma and forms highpower pulse resonance asymmetric AC HEDP magnetron sputtering discharge,thereby causing the HEDP magnetron sputtering discharge to form thelayer of the sputtered target material on the substrate.

The disclosed embodiments also include a computer-readable mediumstoring instructions that, when executed by a processing device, performa method of sputtering a layer on a substrate using a high energydensity plasma (HEDP) magnetron, wherein the method includes operationsinclude configuring an anode and a cathode target magnet assembly to bepositioned in a vacuum chamber with a sputtering cathode target and thesubstrate; applying regulated amplitude unipolar voltage pulses withprogrammed frequency and duration to the tunable PFN, wherein the pulseforming network includes a plurality of inductors and capacitors; andadjusting a pulse voltage for programmed voltage pulses frequency andduration to cause a resonance mode associated with the tunable PFN. Theoutput asymmetric AC waveform is operatively coupled to the sputteringcathode target, and the output asymmetric AC waveform includes anegative voltage exceeding the amplitude of the regulated unipolarvoltage pulses amplitude with programmed frequency and duration duringsputtering discharge of the HEDP magnetron. A further increase in theamplitude of the regulated unipolar voltage pulses with programmedfrequency and duration causes a constant amplitude of the negativevoltage of the output AC waveform in response to the pulse formingnetwork being in the resonance mode, thereby causing the HEDP magnetronsputtering discharge to form the layer on the substrate.

The disclosed embodiments relate to a method of depositing a layer on asubstrate, which includes applying a first magnetic field to a cathodetarget, the first magnetic field generating an unbalanced magnetic fieldand a magnetron configuration on the cathode target; electricallycoupling the cathode target to a first high power pulse resonancealternating current (AC) power supply; positioning an additionalcylindrical cathode target electrode around the cathode; applying asecond magnetic field to the additional cylindrical cathode targetelectrode, wherein the second magnetic field forms a magnetronconfiguration on the cylindrical cathode target electrode; electricallycoupling the additional cylindrical cathode target electrode to a secondhigh power pulse resonance AC power supply; generating magnetic couplingbetween the cathode target and an anode; providing a feed gas; andselecting a time shift between negative voltage peaks associated with ACvoltage waveforms generated by the first high power pulse resonance ACpower supply and the second high power pulse resonance AC power supply,wherein the time shift increases ionization of sputtered target materialatoms associated with the cathode target during sputtering.

The feed gas may include a noble gas, and the noble gas may include atleast one of argon, xenon, neon, krypton. The feed gas may include amixture of a noble gas and a reactive gas. The method may includepositioning a substrate holder, and coupling a substrate bias voltage toa substrate holder. The substrate bias voltage may include a range of−10 V to −200 V. The feed gas may include a mixture of a noble gas and agas that includes atoms of the cathode target material. At least one ofthe first high power pulse resonance AC power supply, second high powerpulse resonance AC power supply may provide an output peak power duringpulse in a range of 10 to 1000 kW.

The disclosed embodiments further relate to an electrically andmagnetically enhanced ionized physical vapor deposition (I-PVD)unbalanced magnetron sputtering apparatus that deposits a layer on asubstrate. The apparatus includes a vacuum chamber; a cathode targetmagnet assembly that generates an unbalanced magnetic field and providesa magnetron configuration on a target surface; a first high power pulseresonance AC power supply connected to the cathode target; an additionalelectrode; an additional electrode magnet assembly that generatesmagnetic coupling between the cathode target and the additionalelectrode; a second high power pulse resonance AC power supply connectedto the additional electrode; and a feed gas. A time shift is disposedbetween negative voltage peaks associated with AC voltage waveformsgenerated by the first high power pulse resonance AC power supply andthe second high power pulse resonance AC power supply. The time shiftincreases ionization of sputtered target material atoms associated withthe cathode target during sputtering.

At least one of the first high power pulse resonance AC power supply,second high power pulse resonance AC power supply may provide a targetpower density during a pulse in a range of 0.1 to 100 kW/cm². Theapparatus may include a substrate bias power supply coupled to asubstrate holder, and the substrate bias power supply may provide a biasvoltage on a substrate in a range of −10 to −200 V. The feed gas mayinclude a noble gas, and the noble gas may include at least one ofargon, xenon, neon, krypton. The feed gas may include a mixture of anoble gas and a reactive gas. The power supply coupled to the cathodemagnet target assembly may include a radio frequency (RF) power supply,and the RF power supply may provide output power in a range of 1 to 20kW. The feed gas may include a mixture of a noble gas and gas thatincludes atoms of the cathode target. The cathode magnet target assemblymay rotate with a speed in a range of 10 to 100 revolutions per minute.

Other embodiments will become apparent from the following detaileddescription considered in conjunction with the accompanying drawings. Itis to be understood, however, that the drawings are designed as anillustration only and not as a definition of the limits of any of theembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are provided by way of example only and withoutlimitation, wherein like reference numerals (when used) indicatecorresponding elements throughout the several views, and wherein:

FIG. 1 shows an illustrative cross-sectional view of magnetic fieldlines of an embodiment of an electrically and magnetically enhancedI-PVD unbalanced magnetron sputtering source with one additionalelectrode magnet assembly;

FIG. 2 shows an illustrative cross-sectional view of magnetic fieldlines of another embodiment of the electrically and magneticallyenhanced I-PVD unbalanced magnetron sputtering source with twoadditional electrode magnet assemblies;

FIG. 3 shows an illustrative view of a bipolar voltage waveform that canbe applied to the anode;

FIG. 4 shows an illustrative cross-sectional view of the anode magnetassembly connected to ground through an inductor and powered with aradio frequency (RF) power supply;

FIG. 5 (a) shows a voltage waveform generated by the RF power supply onthe anode when the anode is not connected to ground through theinductor;

FIG. 5 (b) shows a voltage waveform generated by the RF power supply onthe anode when the anode is not connected to ground through theinductor;

FIG. 6 shows an illustrative cross-sectional view of the electricallyand magnetically enhanced I-PVD unbalanced magnetron sputtering sourcewith an anode magnet assembly;

FIG. 7 (a) shows an illustrative cross-sectional view of theelectrically and magnetically enhanced I-PVD unbalanced magnetronsputtering source including an additional electrode connected with theRF power supply and the cathode target connected to a high-powerresonance pulse forming network (PFN);

FIGS. 7 (b, c) show output voltage waveforms from the high-power pulseresonance forming network (PFN) shown in FIG. 7(a);

FIG. 7 (d) shows an illustrative cross-sectional view of the additionalelectrode and gap electrode assembly;

FIG. 7 (e) shows an illustrative cross-sectional view of the magneticfield lines between magnetron sputtering source and cusp magnetic fieldnear the additional electrode;

FIG. 8 (a) shows an illustrative cross-sectional view of an electricallyand magnetically enhanced I-PVD unbalanced magnetron sputtering system;and

FIG. 8 (b) shows an illustrative cross-sectional view of the additionalelectrode and gap electrode assembly together with the substrate;

FIG. 9 shows a block diagram of at least a portion of an exemplarymachine in the form of a computing system that performs methodsaccording to one or more embodiments disclosed herein.

FIG. 10 (a) shows an illustrative view of a train of output negativeunipolar voltage pulses with amplitude V1 and frequency f1 from ahigh-power resonance pulse forming network (PFN) with programmable pulsevoltage duration and pulse voltage frequency;

FIG. 10 (b) shows an illustrative view of an output resonanceasymmetrical AC voltage waveform with a duration of negative voltage T1from a tunable pulse forming network (PFN);

FIG. 10 (c) shows an illustrative view of a train of output negativeunipolar voltage pulses with amplitude V2 and frequency f1 from ahigh-power resonance pulse forming network (PFN) with programmable pulsevoltage duration and pulse voltage frequency;

FIG. 10 (d) shows an illustrative view of the output resonanceasymmetrical AC voltage waveform with a duration of negative voltage T2from the tunable PFN;

FIG. 10 (e) shows an illustrative view of the output resonanceasymmetrical AC voltage waveform with three oscillations from thetunable PFN;

FIG. 10 (f) shows an illustrative view of the output resonanceasymmetrical AC current waveform with three oscillations from the PFN;

FIG. 10 (g) shows an illustrative cross-sectional view of components andmagnetic field lines of a magnetically enhanced HEDP sputtering sourcewith a stationary cathode target magnetic array;

FIG. 10 (h) shows an illustrative cross-sectional view of a hollowcathode target;

FIG. 11 (a) shows an illustrative circuit diagram of the high-powerresonance pulse forming network (PFN);

FIG. 11 (b) shows an illustrative view of a train of unipolar voltagepulses with frequency f1 and amplitude V1 applied to the tunable PFN,and an output voltage waveform from the tunable PFN without a resonancemode in the tunable PFN;

FIG. 11 (c) shows an illustrative view of a train of unipolar voltagepulses with frequency f2 and amplitude V2 applied to the tunable PFN,and an output voltage waveform from the tunable PFN in a partialresonance mode;

FIG. 11 (d) shows an illustrative view of a train of unipolar voltagepulses with frequency f3 and amplitude V4 applied to the tunable PFN,and an output resonance asymmetrical AC voltage waveform from thetunable PFN in the resonance mode.

FIG. 11 (e) shows an illustrative circuit diagram of the tunable PFNwith the plurality of inductors and capacitors being connected inseries;

FIG. 11 (f) shows an illustrative circuit diagram of the tunable PFNwith the inductors and capacitors being connected in parallel;

FIG. 12 (a) shows an illustrative view of a train of input unipolarnegative voltage pulses with two different voltage amplitudes applied tothe tunable PFN.

FIG. 12 (b) shows an illustrative view of output resonance asymmetricalAC voltage waveform pulses with two different voltage amplitudesgenerated at resonance conditions in the tunable PFN;

FIG. 13 (a) shows an illustrative circuit diagram of the tunable PFN anda plurality of electrical switches;

FIG. 13 (b) shows a train of resonance asymmetrical AC waveforms appliedto different magnetically enhanced sputtering sources;

FIG. 14 (a) shows an illustrative view of the magnetically enhanced HEDPsputtering apparatus;

FIG. 14 (b) shows different voltage pulse shapes that can be generatedby a substrate bias power supply;

FIG. 14 (c) shows an illustrative view of a via in the semiconductorwafer;

FIG. 15 (a) shows a train of resonance asymmetrical AC voltagewaveforms;

FIG. 15 (b) shows a plurality of unipolar voltage pulses generated by ahigh-power resonance pulse forming network (PFN);

FIG. 15 (c) shows a plurality of unipolar RF voltage pulses generated bya pulse RF power supply;

FIG. 16 (a) shows an illustrative circuit diagram of a high-powerresonance pulse forming network (PFN) with an additional high-frequencypower supply;

FIGS. 16 (b, c, d) show illustrative views of trains of oscillatoryunipolar voltage pulses applied to the tunable PFN, and an outputvoltage waveform from the tunable PFN without a resonance mode in thetunable PFN;

FIGS. 17 (a, b) show a hollow cathode target combined from two pieces;

FIG. 18 (a) shows a hollow cathode target combined from two pieces andconnected with two different power supplies;

FIG. 18 (b) shows the voltage output from two high power pulse resonanceAC power supplies;

FIG. 19 shows an illustrative circuit diagram of the high-powerresonance pulse forming network (PFN) that includes a transformer anddiodes;

FIGS. 20 (a)-(g) show different AC voltage waveforms;

FIG. 21 shows arc resonance AC discharge current and arc resonance ACdischarge voltage waveforms;

FIGS. 22 (a, b) show output voltage waveforms from the high-powerresonance pulse forming network (PFN) when connected to the HEDPmagnetron and generating HEDP discharge;

FIG. 23 shows an illustrative view of a hollow cathode HEDP ringmagnetron;

FIG. 24 shows an illustrative view of a segmented hollow cathode HEDPring magnetron;

FIG. 25 (a) shows an illustrative view of tunable PFN;

FIG. 25 (b) shows a cross-sectional view of a V-shaped HEDP sputteringsource;

FIGS. 26 (a, b) show an illustrative view of voltage and currentwaveforms;

FIG. 27 shows an illustrative view of the vacuum process chamber with acathodic arc deposition source, a magnetron sputtering source, and ahollow cathode HEDP magnetron source;

FIG. 28 shows a hollow cathode target combined from two pieces with gasdistribution system; and

FIG. 29 shows an illustrative circuit diagram of the bias power supply.

It is to be appreciated that elements in the figures are illustrated forsimplicity and clarity. Common but well-understood elements that areuseful or necessary in a commercially feasible embodiment are not shownin order to facilitate a less hindered view of the illustratedembodiments.

DETAILED DESCRIPTION

FIG. 1 shows a cross-sectional view 100 of magnetic field lines in anembodiment, in which an additional electrode 106 has one magnetassembly. A cathode magnet assembly 102 includes magnets 103, 104 andmagnetic pole piece 105. The cathode magnet assembly 102 forms amagnetron configuration with magnetic field lines 109 near a surface ofa cathode target 101. A portion of the magnetic field lines 108 crossthe additional electrode 106 and terminate on a magnet 107. Theadditional electrode 106 is connected to a power supply 113. The powersupply 113 can generate positive voltage. In an embodiment, the powersupply 113 can generate high frequency bipolar asymmetrical voltages. Inan embodiment, the power supply 113 can generate a radio frequency (RF)voltage with frequencies in the range of 100 KHz to 100 MHz. In anembodiment, the power supply 113 can generate a negative voltage. When apower supply 112 generates power and a magnetron discharge is formednear the cathode target 101, electrons drift from the surface of thecathode target 101 towards the additional electrode 106. If power supply113 provides a positive voltage, electrons are absorbed by theadditional electrode 106 and the magnetron discharge has a positivespace charge. The positive space charge accelerates a portion of theionized sputtered target material atoms Me⁺ away from the cathode target101 towards a substrate 115. If power supply 113 provides a negativevoltage, electrons are trapped between the cathode target 101 andadditional electrode 106. Some electrons escape on the anode 110, whichhas a ground potential. By controlling the value and duration of thenegative output voltage from the power supply 113, the electron densitycan be controlled. By controlling the value and duration of the positiveoutput voltage from the power supply 113, the ion energy and ion densitynear the substrate 115 can be controlled. In an embodiment, power supply113 generates RF discharge near the surface of the additional electrode106. RF discharge increases electron temperature and electron densityand, therefore, the degree of ionization of sputtered target materialatoms. In an embodiment, power supply 113 generates RF discharge nearthe surface of the additional electrode 106. Additional electrode 106 isinductively grounded. RF discharge increases electron temperature andelectron density and, therefore, the degree of ionization of sputteredtarget material atoms.

FIG. 2 shows a cross-sectional view 200 of magnetic field lines in anembodiment, in which an additional electrode 206 has two magnetassemblies. A cathode magnet assembly 202 includes magnets 203, 204 andmagnetic pole piece 205. An anode 214 is positioned adjacent to thesubstrate 216 and additional electrode 206. The anode 214 is connectedto ground 215. An anode 217 is positioned adjacent to the cathode target201 and connected to ground 215. The cathode magnet assembly 202 forms amagnetron configuration with magnetic field lines 209 near the surfaceof the cathode target 201. A portion of the magnetic field lines 212cross the additional electrode 206 and terminate on the magnet 207. Theadditional electrode 206 is connected to power supply 208. In anembodiment, additional electrode 106 and/or 206 may have a floatingelectrical potential. The power supply 208 can generate floating,negative, or high frequency bipolar voltages. When power supply 210generates power and a magnetron discharge is formed near the cathodetarget 201, electrons drift from the target surface towards theadditional electrode 206. If power supply 208 provides a negativevoltage, electrons are trapped between target 201 and additionalelectrode 206. Some electrons escape on the anode 214, which has aground potential. By controlling the value and duration of the negativeoutput voltage from the power supply, the electron density can becontrolled. The applied negative voltage should not exceed a 40-50 Vsputtering threshold in order to prevent sputtering from the additionalelectrode if the additional electrode is not made from the targetmaterial. Preferably, a negative voltage value should be in the range of−10 to −30 V. The electron density controls the degree of ionization ofsputtered target material atoms. By controlling the value of thepositive output voltage and time duration of the power supply 208, theion energy and ion density near the substrate can be controlled. Atypical rectangular bipolar output voltage provided by power supply 113or 208 is shown in FIG. 3.

Power supplies 113, 208 can be radio frequency (RF) power supplies thatgenerate output voltages with frequencies in the range of 100 kHz to 100MHz, as shown in FIG. 4. RF discharge has rectifying properties andgenerates a negative constant voltage bias VDC on a surface of theadditional electrode 106, 206 as shown in FIG. 5 (a). In order toeliminate this voltage bias and eliminate potential sputtering from theadditional electrode, the additional electrode can be connected toground through an electrical circuit 300 shown in FIG. 4. The electricalcircuit 300 has at least one inductor 301 that has a high impedance forRF frequency signals and a substantially zero impedance for DC currentgenerated by a constant voltage bias. In this case, the additionalelectrodes 106, 206 are inductively grounded. The RF voltage signal,when additional electrodes 106, 206 are connected to electrical circuit300, is shown in FIG. 5(b). In this case, if a DC or pulsed DC powersupply is connected to the cathode target assembly, the additionalelectrode 106, 206 is the anode for only a direct current (DC)discharge. If an RF or pulsed RF power supply is connected to thecathode target assembly, the additional electrode 106, 206 is an anode.For a high frequency component, the anode 110, 214 is used.

FIG. 6 shows a cross-sectional view of an embodiment of the electricallyand magnetically enhanced ionized physical vapor deposition (I-PVD)unbalanced magnetron sputtering source 600. The electrically andmagnetically enhanced I-PVD unbalanced magnetron sputtering source 600includes a housing 601. The housing 601 is electrically connected toground 621. The cathode assembly includes a water jacket 602 and acathode target 607. The cathode target 607 can be bonded to a copperbacking plate 606 or can be attached to the copper backing plate 606with a clamp 631. An anode 633 is positioned adjacent to the cathodetarget 607. The water jacket 602 is electrically isolated from thehousing 601 with isolators 627. Water or another fluid for cooling canmove inside the water jacket 602 through inlet 623 and can flow outsidethe water jacket 602 through the outlet 624. There is an air gap 622between the housing 601 and water jacket 602. The water jacket 602 and,therefore, cathode target 607 are electrically connected to a negativeterminal of a power supply 618 through a transmission line 620. Thepower supply 618 can include a radio frequency (RF) power supply, pulsedRF power supply, high frequency (HF) power supply, pulsed HF powersupply, and a matching network. The power supply 618 can include adirect current (DC) power supply, a pulsed DC power supply thatgenerates unipolar negative voltage pulses, a high power pulsed powersupply, a pulsed DC power supply that generates asymmetrical bipolarvoltage pulses, and/or a pulsed DC power supply that generatessymmetrical bipolar voltage pulses. The power supply 618 can include apulsed power supply that generates negative triangular voltage pulses.The power supply 618 can be a combination of any power suppliesmentioned above. For example, the RF power supply can provide powertogether with the DC power supply, or the pulsed RF power supply canprovide power together with the pulsed DC power supply, or any otherpulse power supply. The frequency of the RF power supply and HF powersupply can be in the range of 500 kHz-100 MHz. All of theabove-mentioned power supplies can operate in current control mode,voltage control mode, and/or power control mode.

The cathode target 607 is formed in the shape of a disk, but can beformed in other shapes, such as a rectangle, and the like. The cathodetarget 607 material can be conductive, semi-conductive, and/ornon-conductive. The following chemical elements, or their combination,can be used as a cathode material: B, C, Al, Si, P, S, Ga, Ge, As, Se,In, Sn, Sb, Te, I, Tl, Pb, Bi, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y,Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au,La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Be, Mg, Ca, Sr,and/or Ba. A combination of these chemical elements or their combinationwith the gases O₂, N₂, F, Cl, and/or H₂ can also be used as a cathodematerial. Power supply 618 can be connected to a controller 625 andcomputer 626. Controller 625 and/or computer 626 control the outputpower values and timing of the power supplies 618 and 617. Power supply618 can operate as a standalone unit without connecting to thecontroller 625 and/or computer 626.

The cathode assembly includes a cathode magnetic assembly 630 positionedinside the water jacket 602. The cathode magnetic assembly 630 in anembodiment includes magnets 604, 603, and a disc-shaped magnetic polepiece 605 made from magnetic material, such as iron. Magnets 604, 603form a magnetron configuration on the surface of the cathode target 607.The magnetron configuration has magnetic field lines 615.

A ring-shaped additional electrode 609 is positioned around the cathodetarget 607 on a supporter 632. An additional electrode magnet assemblyhas a cylindrical shape and is positioned behind a ring-shapedadditional electrode 609 in the supporter 632. The anode magnet assemblyincludes a plurality of permanent magnets 611. In an embodiment, ratherthan using permanent magnets, electromagnets can be used. The value ofthe magnetic field caused by the permanent magnets 611 is in a range of100 to 1000 G. The magnets 611 provide magnetic coupling with magnet 603and, therefore, with a surface of the target 607 through magnetic fieldlines 616. In an embodiment, the magnet 611 provides magnetic couplingwith magnets 604.

The additional electrode 609 is electrically isolated from a groundshield 628 by isolators 614, 610, 613. The additional electrode 609 isconnected to power supply 617 through transmission line 619 andelectrode 612. Power supply 617 can be connected to controller 625.

The magnetic fields 616 shown in FIG. 6 are shaped to provide electronmovement between the cathode target 607 and additional electrode 609.During this movement, electrons ionize and/or dissociate feed gasmolecules and/or sputtered target material atoms.

FIG. 7 (a) shows the additional electrode 701 connected to RF powersupply 704 and inductively grounded through inductor 705 and switch 706.The cathode target 703 is connected to a high power pulsed power supplythat generates oscillatory voltage with frequency in a range of 10 to100 KHz. The block diagram of the high power supply shows a capacitor orcapacitor bank 713 and solid state switch 712, which can release energyfrom the capacitor 713 to transformer 711. Transformer 711, diodes 710,inductors 709, and capacitor 708 form oscillatory voltage waveforms, asshown in FIGS. 7 (b), (c).

In an embodiment, the additional electrode 738 is positioned behind thegap 739 as shown in FIG. 7 (d). The additional electrode 738 has tworows of permanent magnets that form a cusp magnetic field in the gap739. Two pole pieces 736, 731 are positioned on top and bottom of themagnets 728, 729. Additional electrode 738 has anode 723. The anode 723has feed gas chamber 725 and feed gas inlet 724. The fed gas entersthrough a plurality of cylindrical holes 727. The additional electrodecan be connected to a power supply 732 through transmission line 735.The power supply 732 can be an RF power supply that generates outputvoltage with frequencies in the range of 100 KHz to 100 MHz. The powersupply 732 can be a pulsed power supply or DC (direct current) powersupply. The additional electrode 738 can be grounded through inductor755. The gap 739 is formed between the anode 723 and gap electrode 722.The gap electrode 722 is positioned behind the grounded shield 720. Theadditional electrode 738 is positioned on the isolator 730. The gapelectrode 722 is positioned on isolator 721. The gap electrode isconnected to the power supply 733. The power supply 733 can be an RFpower supply that generates output voltage with frequencies in the rangeof 100 KHz to 100 MHz. The power supply 733 can be a pulsed power supplyor DC power supply. The gap electrode 722 can be grounded throughinductor 754. The electric field in the gap 739 is substantiallyperpendicular to magnetic field lines. The magnetic field lines areshown in FIG. 7 (e). In an embodiment, the gap electrode 722 has aground potential, and power supply 732 releases voltage on additionalelectrode 738. In an embodiment, additional electrode 738 has a groundpotential or floating potential, and power supply 733 releases voltageon gap electrode 722.

Magnetic field lines are shown in FIG. 7 (e). Magnets 750, 751 andmagnetic pole piece 752 form a magnetron configuration on the cathodetarget 753. Magnets 728 and 729 form a cusp magnetic field 754.

The electrically and magnetically enhanced I-PVD unbalanced magnetronsputtering source 600 can be mounted inside a vacuum chamber 801 asshown in FIG. 8 in order to construct the electrically and magneticallyenhanced I-PVD unbalanced magnetron sputtering apparatus 800. The vacuumchamber 801 contains feed gas and plasma. The vacuum chamber 801 iscoupled to ground 816. The vacuum chamber 801 is positioned in fluidcommunication with a vacuum pump 803, which can evacuate the feed gasfrom the vacuum chamber 801. Typical baseline pressure in the vacuumchamber 801 is in a range of 10⁻⁶-10⁻⁹ Torr.

A feed gas is introduced into the vacuum chamber 801 through a gas inlet804 from a feed gas source. In an embodiment, a feed gas is introducedinto the vacuum chamber 801 through a gas activation source 802. A massflow controller 805 controls gas flow to the vacuum chamber 801. In anembodiment, the vacuum chamber 801 has a plurality of gas inlets andmass flow controllers. The gas flow can be in a range of 1 to 1000 SCCMdepending on plasma operating conditions, pumping speed of the vacuumpump 803, process conditions, and the like. Typical gas pressure in thevacuum chamber 801 during a sputtering process can be in a range of 0.1mTorr to 100 mTorr. In an embodiment, a plurality of gas inlets and aplurality of mass flow controllers sustain a desired gas pressure duringthe sputtering process. The plurality of gas inlets and plurality ofmass flow controllers may be positioned in the vacuum chamber 801 atdifferent locations. The feed gas can be a noble gas, such as Ar, Ne,Kr, Xe; a reactive gas, such as N₂, O₂; or any other gas that aresuitable for sputtering or reactive sputtering processes. The feed gascan also be a mixture of noble and reactive gases. The feed gas can be agas that contains the same atoms as a target material.

In an embodiment, the target material is carbon. The feed gases are C₂H₂or any other gas that contains carbon atoms and a noble gas such asargon.

FIG. 8 shows an embodiment of an electrically and magnetically enhancedmagnetron sputtering apparatus 800, which includes a substrate support808 that holds a substrate 807 or other work piece for plasmaprocessing. The substrate support 808 is electrically connected to abias voltage power supply 809. The bias voltage power supply 809 caninclude a radio frequency (RF) power supply, alternating current (AC)power supply, very high frequency (VHF) power supply, direct current(DC) power supply, and/or high power pulse power supply. The bias powersupply 809 can operate in continuous mode or pulse mode. The bias powersupply 809 can be combination of different power supplies that canprovide different frequencies. The negative bias voltage on thesubstrate can be in a range of 0 and −2000 V. The negative substratebias voltage can attract positive ions to the substrate. At biasvoltages in the range of −800 V to −1000 V, the ions from sputteredtarget material atoms can etch substrate surface. At higher biasvoltage, sputtered target material ions can be implanted to substratesurface. The substrate support 808 can include a heater 817 that isconnected to a temperature controller (not shown). The temperaturecontroller regulates the temperature of the substrate 807. In anembodiment, the temperature controller controls the temperature of thesubstrate 807 to be in a range of −20 C to 400 C.

The cathode target from the electrically and magnetically enhancedmagnetron sputtering source is connected to power supply 811 throughtransmission line 813. The additional electrode from the electricallyenhanced sputtering source is connected to power supply 814 through thetransmission line 815. If power supply 814 is an RF power supply, theadditional electrode can be inductively grounded through inductor 806and switch 810. In an embodiment, there is no switch 810. If powersupply 811 is an RF power supply, the additional cathode target assemblycan be inductively grounded through inductor 821 and switch 820. In anembodiment, there is no switch 820.

During sputtering, a noble gas, such as argon, is flowing in the chamber801 through inlet 804 or gas activation source 802. The gas pressure canbe in the range of 0.5-50 mTorr. The substrate bias can be between −10 Vand −200 V. In an embodiment, power supply 811 generates pulsed powerwith triangular or rectangular voltage pulse shapes or any other voltagepulse shapes. The pulsed power supply can generate asymmetrical bipolarpulses. At the same time, power supply 814 generates pulsed orcontinuous RF discharge near the additional electrode. This RF dischargeincreases the electron energy and electron density, thereby increasingthe ionization rate of the sputtered target material atoms. That is, thepulsed power supply connected to the cathode target controls thedeposition rate, and the RF power supply that is connected to theadditional electrode controls plasma density and electron energy. The RFpower can be in the range of 1-20 kW. In an embodiment, power supply 811generates DC power. The DC power can be in the range of 1-100 kWdepending on the area of the cathode target.

In an embodiment, a cathode target magnet assembly includes multiplesmall magnetrons. In an embodiment, one part of the cathode targetmagnet assembly forms a magnetron configuration and another part forms anon-magnetron configuration.

The electrically and magnetically enhanced ionized physical vapordeposition (I-PVD) unbalanced magnetron sputtering apparatus can beconfigured for chemically enhanced I-PVD, plasma enhanced CVD, reactiveion etch (RIE), or sputter etch applications. Typically, for CVD, RIE,and sputter etch applications, the cathode target assembly andadditional electrodes are connected to the RF power supplies and areinductively grounded. The RF frequency on the additional electrode andcathode target assembly can be different. In an embodiment, the RFfrequency on the additional electrode is 27 MHz, and the RF frequency onthe cathode target assembly is 13.56 MHz. The RF power supplies 814, 811can be pulsed RF power supplies and can be synchronized. The cathodetarget magnet assembly for CVD, RIE, and sputter etch applications canhave magnet assemblies that generate magnetic field lines, which aresubstantially perpendicular to the cathode surface.

In some embodiments, the assembly of the additional electrode and thegap electrode shown in FIG. 7 (d) can be used separately from themagnetron sputtering source shown in FIG. 8 (b). A substrate 760 ispositioned on the magnetic pole piece 761 and heater 762. Supporter 763is connected to substrate bias power supply 764. This configuration canbe used for CVD and RIE applications.

One or more embodiments disclosed herein, or a portion thereof, may makeuse of software running on a computer or workstation. By way of example,only and without limitation, FIG. 9 is a block diagram of an embodimentof a machine in the form of a computing system 900, within which is aset of instructions 902 that, when executed, cause the machine toperform any one or more of the methodologies according to embodiments ofthe invention. In one or more embodiments, the machine operates as astandalone device; in one or more other embodiments, the machine isconnected (e.g., via a network 922) to other machines. In a networkedimplementation, the machine operates in the capacity of a server or aclient user machine in a server-client user network environment.Exemplary implementations of the machine as contemplated by embodimentsof the invention include, but are not limited to, a server computer,client user computer, personal computer (PC), tablet PC, personaldigital assistant (PDA), cellular telephone, mobile device, palmtopcomputer, laptop computer, desktop computer, communication device,personal trusted device, web appliance, network router, switch orbridge, or any machine capable of executing a set of instructions(sequential or otherwise) that specify actions to be taken by thatmachine.

The computing system 900 includes a processing device(s) 904 (e.g., acentral processing unit (CPU), a graphics processing unit (GPU), orboth), program memory device(s) 906, and data memory device(s) 908,which communicate with each other via a bus 910. The computing system900 further includes display device(s) 912 (e.g., liquid crystal display(LCD), flat panel, solid state display, or cathode ray tube (CRT)). Thecomputing system 900 includes input device(s) 914 (e.g., a keyboard),cursor control device(s) 916 (e.g., a mouse), disk drive unit(s) 918,signal generation device(s) 920 (e.g., a speaker or remote control), andnetwork interface device(s) 924, operatively coupled together, and/orwith other functional blocks, via bus 910.

The disk drive unit(s) 918 includes machine-readable medium(s) 926, onwhich is stored one or more sets of instructions 902 (e.g., software)embodying any one or more of the methodologies or functions herein,including those methods illustrated herein. The instructions 902 mayalso reside, completely or at least partially, within the program memorydevice(s) 906, the data memory device(s) 908, and/or the processingdevice(s) 904 during execution thereof by the computing system 900. Theprogram memory device(s) 906 and the processing device(s) 904 alsoconstitute machine-readable media. Dedicated hardware implementations,such as but not limited to ASICs, programmable logic arrays, and otherhardware devices can likewise be constructed to implement methodsdescribed herein. Applications that include the apparatus and systems ofvarious embodiments broadly comprise a variety of electronic andcomputer systems. Some embodiments implement functions in two or morespecific interconnected hardware modules or devices with related controland data signals communicated between and through the modules, or asportions of an ASIC. Thus, the example system is applicable to software,firmware, and/or hardware implementations.

The term “processing device” as used herein is intended to include anyprocessor, such as, for example, one that includes a CPU (centralprocessing unit) and/or other forms of processing circuitry. Further,the term “processing device” may refer to more than one individualprocessor. The term “memory” is intended to include memory associatedwith a processor or CPU, such as, for example, RAM (random accessmemory), ROM (read only memory), a fixed memory device (for example,hard drive), a removable memory device (for example, diskette), a flashmemory and the like. In addition, the display device(s) 912, inputdevice(s) 914, cursor control device(s) 916, signal generation device(s)920, etc., can be collectively referred to as an “input/outputinterface,” and is intended to include one or more mechanisms forinputting data to the processing device(s) 904, and one or moremechanisms for providing results associated with the processingdevice(s). Input/output or I/O devices (including but not limited tokeyboards (e.g., alpha-numeric input device(s) 914, display device(s)912, and the like) can be coupled to the system either directly (such asvia bus 910) or through intervening input/output controllers (omittedfor clarity).

In an integrated circuit implementation of one or more embodiments ofthe invention, multiple identical die are typically fabricated in arepeated pattern on a surface of a semiconductor wafer. Each such diemay include a device described herein, and may include other structuresand/or circuits. The individual dies are cut or diced from the wafer,then packaged as integrated circuits. One skilled in the art would knowhow to dice wafers and package die to produce integrated circuits. Anyof the exemplary circuits or method illustrated in the accompanyingfigures, or portions thereof, may be part of an integrated circuit.Integrated circuits so manufactured are considered part of thisinvention.

An integrated circuit in accordance with the embodiments of the presentinvention can be employed in essentially any application and/orelectronic system in which buffers are utilized. Suitable systems forimplementing one or more embodiments of the invention include, but arenot limited, to personal computers, interface devices (e.g., interfacenetworks, high-speed memory interfaces (e.g., DDR3, DDR4), etc.), datastorage systems (e.g., RAID system), data servers, etc. Systemsincorporating such integrated circuits are considered part ofembodiments of the invention. Given the teachings provided herein, oneof ordinary skill in the art will be able to contemplate otherimplementations and applications.

In accordance with various embodiments, the methods, functions or logicdescribed herein is implemented as one or more software programs runningon a computer processor. Dedicated hardware implementations including,but not limited to, application specific integrated circuits,programmable logic arrays and other hardware devices can likewise beconstructed to implement the methods described herein. Further,alternative software implementations including, but not limited to,distributed processing or component/object distributed processing,parallel processing, or virtual machine processing can also beconstructed to implement the methods, functions or logic describedherein.

The embodiment contemplates a machine-readable medium orcomputer-readable medium containing instructions 902, or that whichreceives and executes instructions 902 from a propagated signal so thata device connected to a network environment 922 can send or receivevoice, video or data, and to communicate over the network 922 using theinstructions 902. The instructions 902 are further transmitted orreceived over the network 922 via the network interface device(s) 924.The machine-readable medium also contains a data structure for storingdata useful in providing a functional relationship between the data anda machine or computer in an illustrative embodiment of the systems andmethods herein.

While the machine-readable medium 902 is shown in an example embodimentto be a single medium, the term “machine-readable medium” should betaken to include a single medium or multiple media (e.g., a centralizedor distributed database, and/or associated caches and servers) thatstore the one or more sets of instructions. The term “machine-readablemedium” shall also be taken to include any medium that is capable ofstoring, encoding, or carrying a set of instructions for execution bythe machine and that cause the machine to perform anyone or more of themethodologies of the embodiment. The term “machine-readable medium”shall accordingly be taken to include, but not be limited to:solid-state memory (e.g., solid-state drive (SSD), flash memory, etc.);read-only memory (ROM), or other non-volatile memory; random accessmemory (RAM), or other re-writable (volatile) memory; magneto-optical oroptical medium, such as a disk or tape; and/or a digital file attachmentto e-mail or other self-contained information archive or set of archivesis considered a distribution medium equivalent to a tangible storagemedium. Accordingly, the embodiment is considered to include anyone ormore of a tangible machine-readable medium or a tangible distributionmedium, as listed herein and including art-recognized equivalents andsuccessor media, in which the software implementations herein arestored.

It should also be noted that software, which implements the methods,functions and/or logic herein, are optionally stored on a tangiblestorage medium, such as: a magnetic medium, such as a disk or tape; amagneto-optical or optical medium, such as a disk; or a solid statemedium, such as a memory automobile or other package that houses one ormore read-only (non-volatile) memories, random access memories, or otherre-writable (volatile) memories. A digital file attachment to e-mail orother self-contained information archive or set of archives isconsidered a distribution medium equivalent to a tangible storagemedium. Accordingly, the disclosure is considered to include a tangiblestorage medium or distribution medium as listed herein and otherequivalents and successor media, in which the software implementationsherein are stored.

Although the specification describes components and functionsimplemented in the embodiments with reference to particular standardsand protocols, the embodiment are not limited to such standards andprotocols.

The disclosed embodiments may also relate to a high energy densityplasma (HEDP) magnetically enhanced sputtering source, apparatus, andmethod for sputtering hard coatings in the presence of high-power pulseasymmetrical alternating current (AC) waveforms. The high power pulseasymmetric AC waveform is generated by having a regulated voltage sourcewith variable power feeding a regulated voltage to the high power pulsesupply with programmable pulse voltage duration and pulse voltagefrequency producing at its output a train of regulated amplitudeunipolar negative voltage pulses with programmed pulse frequency andduration and supplying these pulses to a tunable pulse forming network(PFN) including a plurality of inductors and capacitors for pulseapplications connected in a specific format coupled to a magneticallyenhanced sputtering source. By adjusting the pulse voltage amplitude,duration, and frequency of the unipolar negative voltage pulses andtuning the values of the inductors and capacitors in the PFN coupled toa magnetically enhanced sputtering source, a resonance pulsed asymmetricAC discharge is achieved.

Another method to produce a resonance pulsed asymmetric AC discharge isto have fixed unipolar pulse power supply parameters (amplitude,frequency, and duration) feeding a pulse forming network, in which thenumerical values of the inductors and capacitors, as well as theconfiguration can be tuned to achieve the desired resonance values onthe HEDP source to form a layer on the substrate. The tuning of the PFNcan be done manually with test equipment, such as an oscilloscope,voltmeter and current meter or other analytical equipment; orelectronically with a built-in software algorithm, variable inductors,variable capacitors, and data acquisition circuitry. The negativevoltage from the pulse asymmetric AC waveform generates high densityplasma from feed gas atoms and sputtered target material atoms betweenthe cathode sputtering target and the anode of the magnetically enhancedsputtering source. The positive voltage from the pulse asymmetrical ACwaveform attracts plasma electrons to the cathode sputtering area andgenerates positive plasma potential. The positive plasma potentialaccelerates gas and sputtered target material ions from the cathodesputtering target area towards the substrate that improve depositionrate and ion bombardment on the substrate. The reverse electron currentcan be up to 50% from the discharge current during negative voltage.

In some embodiments, the magnetically enhanced sputtering source is ahollow cathode magnetron. The hollow cathode magnetron includes a hollowcathode sputtering target, and the tunable PFN has a plurality ofcapacitors and inductors. The resonance mode associated with the tunablePFN is a function of the input unipolar voltage pulse amplitude,duration, and frequency generated by the high power pulse power supply,inductance, resistance and capacitance of the hollow cathode magnetronor any other magnetically enhanced device, the inductance, capacitance,and resistance of the cables between the tunable PFN and hollow cathodemagnetron, and a plasma impedance of the hollow cathode magnetronsputtering source itself as well as the sputtered material.

In some embodiments, rather than the hollow cathode magnetron, acylindrical magnetron is connected to an output of the tunable PFN. Insome embodiments, rather than the hollow cathode magnetron, a magnetronwith flat target is connected to the output of the tunable PFN. In theresonance mode, the output negative voltage amplitude of the high powerpulse voltage mode asymmetrical AC waveform on the magnetically enhanceddevice exceeds the negative voltage amplitude of the input unipolarvoltage pulses into the tunable PFN by 1.1-5 times. The unipolarnegative high power voltage output can be in the range of 400V-5000V. Inthe resonance mode, the absolute value of the negative voltage amplitudeof the asymmetrical AC waveform can be in the range of 750-10000 V. Inthe resonance mode, the output positive voltage amplitude of theasymmetrical AC waveform can be in the range of 100-5000 V. In somecases, the resonance mode of the negative voltage amplitude of theoutput AC waveform can reach a maximum absolute value while holding allother component parameters (such as the pulse generator output, PFNvalues, cables and HEDP source) constant, wherein a further increase ofthe input voltage to the tunable PFN does not result in a voltageamplitude increase on the HEDP source, but rather an increase in theduration of the negative pulse in the asymmetric AC waveform on the HEDPsource.

Sputtering processes are performed with a magnetically and electricallyenhanced HEDP plasma source positioned in a vacuum chamber. As mentionedabove, the plasma source can be any magnetically enhanced sputteringsource with a different shape of sputtering cathode target. Magneticenhancement can be performed with electromagnets, permanent magnets,stationary magnets, moveable magnets, and/or rotatable magnets. In thecase of a magnetron sputtering source, the magnetic field can bebalanced or unbalanced. A typical power density of the HEDP sputteringprocess during a negative portion of the high voltage AC waveform is inthe range of 0.1-20 kW/cm′. A typical discharge current density of theHEDP sputtering process during a negative portion of the high voltage ACwaveform is in the range of 0.1-20 A/cm². In the case of the hollowcathode magnetron sputtering source, the magnetic field lines form amagnetron configuration on a bottom surface of the hollow cathode targetfrom the hollow cathode magnetron. Magnetic field lines aresubstantially parallel to the bottom surface of the hollow cathodetarget and partially terminate on the bottom surface and side walls ofthe hollow cathode target. The height of the side walls can be in therange of 5-100 mm. Due to the presence of side walls on the hollowcathode target, electron confinement is significantly improved whencompared with a flat target in accordance with the disclosedembodiments. In some embodiments, an additional magnet assembly ispositioned around the walls of the hollow cathode target. In someembodiments, there is a magnetic coupling between additional magnets anda magnetic field forms a magnetron configuration.

Since the high power resonance asymmetric AC waveform can generate HEDPplasma and, therefore, significant power on the magnetically enhancedsputtering source, the AC waveform is pulsed in programmable bursts toprevent damage to the magnetically enhanced sputtering source fromexcess average power. The programmable duration of the AC pulse burstscan be in the range of 0.1-100 ms. The frequency of the programmable ACpulse bursts can be in the range of 1 Hz-10000 Hz. In some embodiments,the AC waveform is continuous or has a 100% duty cycle assuming the HEDPplasma source can handle the average power. The frequency of the pulsedAC waveform inside the programmable pulse bursts can be programmed inthe range of 100 Hz-400 kHz with a single frequency or mixed frequency.

The magnetically enhanced HEDP sputtering source includes a magnetronwith a sputtering cathode target, an anode, a magnet assembly, aregulated voltage source connected to a high power pulsed power supplywith programmable output pulse voltage amplitude, frequency, andduration. The pulsed power supply is connected to the input of thetunable PFN, and the output of the tunable PFN is connected to thesputtering cathode target on the magnetically enhanced sputteringsource. The tunable PFN, in resonance mode, generates the high powerresonance asymmetrical AC waveform and provides HEDP on the magneticallyenhanced sputtering source.

The magnetically enhanced high power pulse resonance asymmetric AC HEDPsputtering source may include a hollow cathode magnetron with a hollowcathode sputtering target, a second magnet assembly positioned aroundthe side walls of the hollow cathode target, an electrical switchpositioned between the tunable PFN and hollow cathode magnetron with aflat sputtering target rather than a hollow cathode shape, and amagnetic array with permanent magnets, electromagnets, or a combinationthereof.

The magnetically enhanced high power pulse resonance asymmetric AC HEDPsputtering apparatus includes a magnetically enhanced HEDP sputteringsource, a vacuum chamber, a substrate holder, a substrate, a feed gasmass flow controller, and a vacuum pump.

The magnetically enhanced high power pulse resonance asymmetric AC HEDPsputtering apparatus may include one or more electrically andmagnetically enhanced HEDP sputtering sources, substrate heater,controller, computer, gas activation source, substrate bias powersupply, matching network, electrical switch positioned between thetunable PFN and magnetically enhanced HEDP sputtering source, and aplurality of electrical switches connected with a plurality ofmagnetically enhanced high power pulse resonance asymmetric AC HEDPsputtering sources and output of the tunable PFN.

A method of providing high power pulse resonance asymmetric AC HEDP filmsputtering includes positioning a magnetically enhanced sputteringsource inside a vacuum chamber, connecting the cathode target to theoutput of the tunable PFN that, in resonance mode, generating the highpower asymmetrical AC waveform, positioning a substrate on a substrateholder, providing feed gas, programing voltage pulses frequency andduration, adjusting pulse voltage amplitude of the programmed voltagepulses with fixed frequency and duration feeding the tunable PFN,generating the output high voltage asymmetrical AC waveform with anegative voltage amplitude that exceeds the negative voltage amplitudeof the voltage pulses in the resonance mode, thereby resulting in a highpower pulse resonance asymmetric AC HEDP discharge.

The method of magnetically enhanced high power pulse resonanceasymmetric AC HEDP film sputtering may include positioning an electricalswitch between the hollow cathode magnetron and the tunable PFN that, inresonance mode, generates the high voltage asymmetrical AC waveform,applying heat to the substrate or cooling down the substrate, applyingdirect current (DC) or radio frequency (RF) continuously and/or using apulse bias voltage to the substrate holder to generate a substrate bias,connecting the tunable PFN that, in resonance mode, generates the highvoltage asymmetrical AC waveform simultaneously to the plurality ofhollow cathode magnetrons or magnetrons with flat targets, and ignitingand sustaining simultaneously HEDP in the plurality of the hollowcathode magnetron.

The disclosed embodiments include a method of sputtering a layer on asubstrate using a high power pulse resonance asymmetric AC HEDPmagnetron. The method includes configuring an anode and a cathode targetmagnet assembly to be positioned in a vacuum chamber with a sputteringcathode target and the substrate, applying high power negative unipolarvoltage pulses with regulated amplitude and programmable duration andfrequency to a tunable PFN, wherein the tunable PFN includes a pluralityof inductors and capacitors, and adjusting an amplitude associated withthe unipolar voltage pulses with programmed duration and frequency tocause a resonance mode associated with the tunable pulse forming networkto produce an output high power pulse resonance asymmetric AC on theHEDP sputtering source. The output AC waveform from the tunable PFN isoperatively coupled to the HEDP sputtering cathode target, and theoutput high power pulse resonance asymmetric AC waveform includes anegative voltage exceeding the amplitude of the input unipolar voltagepulses to the tunable PFN during the resonance mode and sputteringdischarge of the HEDP magnetron. With all conditions fixed, any furtherincrease of the amplitude of the unipolar voltage pulses causes only anincrease in the duration of the maximum value of the negative voltageamplitude of the output high power asymmetric AC waveform in response tothe pulse forming network being in the resonance mode, thereby causingthe HEDP magnetron sputtering discharge to form the layer on thesubstrate.

The disclosed embodiments further include an apparatus that sputters alayer on a substrate using a high-power pulse resonance asymmetric ACHEDP magnetron. The apparatus includes an anode, cathode target magnetassembly, regulated high voltage source with variable power, high powerpulse power supply with programmable voltage pulse duration andfrequency power supply, and a tunable PFN. The anode and cathode targetmagnet assembly are configured to be positioned in a vacuum chamber witha sputtering cathode target and the substrate. The high power pulsepower supply generates programmable unipolar negative voltage pulseswith defined amplitude, frequency, and duration. The tunable pulseforming network includes a plurality of inductors and capacitors, andthe amplitude of the voltage pulses are adjusted to be in the resonancemode associated with the tunable PFN and magnetically enhancedsputtering source for specific programmed pulse parameters, such asamplitude, frequency and duration of the unipolar voltage pulses. Theoutput of the tunable PFN is operatively coupled to the sputteringcathode target, and the output of the tunable PFN in the resonance modegenerates a high power resonance asymmetric AC waveform that includes anegative voltage exceeding the amplitude of the input to tunable PFNunipolar voltage pulses. An AC waveform sustains plasma and forms highpower pulse resonance asymmetric AC HEDP magnetron sputtering discharge,thereby causing the HEDP magnetron sputtering discharge to form thelayer of the sputtered target material on the substrate.

The disclosed embodiments also include a computer-readable mediumstoring instructions that, when executed by a processing device, performa method of sputtering a layer on a substrate using a high energydensity plasma (HEDP) magnetron, wherein the operations includeconfiguring an anode and a cathode target magnet assembly to bepositioned in a vacuum chamber with a sputtering cathode target and thesubstrate, applying regulated amplitude unipolar voltage pulses withprogrammed frequency and duration to the tunable PFN, wherein the pulseforming network includes a plurality of inductors and capacitors, andadjusting a pulse voltage for programmed voltage pulses frequency andduration to cause a resonance mode associated with the tunable PFN. Theoutput asymmetric AC waveform is operatively coupled to the sputteringcathode target, and the output asymmetric AC waveform includes anegative voltage exceeding the amplitude of the regulated unipolarvoltage pulses amplitude with programmed frequency and duration duringsputtering discharge of the HEDP magnetron. A further increase in theamplitude of the regulated unipolar voltage pulses with programmedfrequency and duration causes a constant amplitude of the negativevoltage of the output AC waveform in response to the pulse formingnetwork being in the resonance mode, thereby causing the HEDP magnetronsputtering discharge to form the layer on the substrate.

Other embodiments will become apparent from the following detaileddescription considered in conjunction with the accompanying drawings. Itis to be understood, however, that the drawings are designed as anillustration only and not as a definition of the limits of any of theembodiments.

A high energy density plasma (HEDP) magnetically enhanced sputteringsource includes a hollow cathode magnetron, pulse power supply, andtunable pulse forming network (PFN). The tunable PFN, in resonance mode,generates a high voltage asymmetrical alternating current (AC) waveformwith a frequency in the range of 400 Hz to 400 kHz. The resonance modeof the tunable PFN, as used herein, is a mode in which input negativeunipolar voltage pulses with adjusted amplitude, and programmedduration, and frequency generate an output high power resonance pulseasymmetric AC waveform with negative amplitude that exceeds the negativeamplitude of the input negative unipolar voltage pulses. Furtherincrease of the amplitude of the input negative unipolar voltage pulsesfrom the high power pulse power supply does not increases the negativeamplitude of the output high resonance asymmetric AC voltage waveform,but increases the duration of the maximum value of the negativeresonance AC voltage waveform as shown in FIGS. 10 (a, b, c, d). Whenthe amplitude of the input unipolar negative voltage pulses equals V1 asshown in FIG. 10 (a) at the output of the tunable PFN during the HEDPdischarge, there is an asymmetrical resonance AC voltage waveform asshown in FIG. 10 (b). The resonance asymmetrical AC voltage waveform hasa negative portion V⁻ with a duration τ1, and positive portions V₁ ⁺ andV₂ ⁺. When the amplitude voltage becomes V2 and V2>V1, the amplitude ofthe resonance negative AC voltage waveform is the same as V3, but theduration is τ2 and τ2>τ1. A negative portion of the resonanceasymmetrical AC voltage waveform generates AC discharge current I₁ andpositive voltage generates discharge current I₂ as shown in FIGS. 10 (e,f). A negative portion of the high power asymmetrical resonance ACvoltage waveform generates HEDP magnetron discharge from feed gas andsputtering target material atoms inside a hollow cathode target due tohigh discharge voltage and improved electron confinement. During thesputtering process, the hollow cathode target power density is in therange of 0.1 to 20 kW/cm². A positive portion of the high voltageasymmetrical AC voltage waveform provides absorption of electrons fromthe HEDP by the hollow cathode magnetron surface and, therefore,generates a positive plasma potential that causes ions to acceleratetowards the hollow cathode target walls and a substrate. The ion energyis a function of the amplitude and duration of the positive voltage. Theduration of the maximum absolute value of the negative voltage from thehigh voltage asymmetrical AC voltage waveform is in the range of0.001-to 100 ms. The discharge current during the positive voltage ofthe asymmetrical resonance AC voltage waveform can be in the range of5-50% of the discharge current during the negative voltage from the ACvoltage waveform.

The high power pulse resonance asymmetric AC HEDP magnetron sputteringprocess is substantially different from high power impulse magnetronsputtering (HIPIMS) due to the resonance AC nature of the dischargegenerated by the tunable PFN and HEDP magnetron discharge. The resonanceasymmetrical high power AC discharge is substantially more stable whencompared with HIPIMS discharge. In the resonance mode, the high power ACwaveform can be symmetrical or asymmetrical. For example, for a carbonhollow cathode magnetron, a sputtering process with stable AC dischargecurrent density of about 6 A/cm² is obtained. The disclosed embodimentsrelate to ionized physical vapor deposition (I-PVD) with an HEDPsputtering apparatus and method.

A sputtering process can be performed with a hollow cathode magnetronsputtering source and direct current (DC) power supply. An example ofsuch an apparatus and sputtering process is described in Zhehui Wang andSamuel A. Cohen, Hollow cathode magnetron, J. Vac. Sci. Technol., Vol.17, January/February 1999, which is incorporated by reference herein inits entirety. However, these techniques do not address operation of ahollow cathode magnetron sputtering source with a high voltageasymmetrical AC voltage waveform, a method of accelerating ions from thefeed gas and sputtering target material atoms by controlling a positivevoltage portion of a high power asymmetrical resonance AC waveformapplied to an entirely hollow cathode magnetron, or operation of a pulsepower supply and tunable PFN when the tunable PFN is in a resonant modeand generating a high power resonance asymmetrical AC waveform on ahollow cathode magnetron sputtering source.

A magnetically and electrically enhanced HEDP sputtering source 1000shown in FIG. 10 (g) includes a hollow cathode magnetron 1010 and a highpower pulse resonance AC power supply 1020, which includes a high powervoltage source 1190, a high power pulsed power supply with programmablevoltage pulse frequency and amplitude 1200, and tunable PFN 1240. Thistunable PFN, in resonance mode, generates a high power resonanceasymmetrical AC waveform. The hollow cathode magnetron 1010 includes ahollow cathode target 1030. The hollow cathode target 1030 has sidewalls 1040 and a bottom part 1050 as shown in FIGS. 10 (g), (h). Ananode 1060 is positioned around the side walls 1040. Magnets 1070, 1080,and magnetic pole piece 1090 are positioned inside a water jacket 1100.The water jacket 1100 is positioned inside a housing 1110. The hollowcathode target 1030 is bonded to a copper backing plate 1120. Magnets1070, 1080 and magnetic pole piece 1090 generate magnetic field lines1130, 1140 that terminate on a bottom part 1050 and form a magnetronconfiguration. Magnetic pole piece 1090 is positioned on a supporter1240. Magnetic field lines 1150, 1160 terminate on the side walls 1040.Water jacket 1100 has a water inlet 1170 and a water outlet 1180. Thewater inlet 1170 and water outlet 1180 are isolated from housing 1110 byisolators 1210. Water jacket 1100 and, therefore, hollow cathode target1010 are connected to a high power pulse resonance AC power supply 1020.The following chemical elements, or a combination of any two or more ofthese elements, can be used as a cathode material: B, C, Al, Si, P, S,Ga, Ge, As, Se, In, Sn, Sb, Te, I, Tl, Pb, Bi, Sc, Ti, Cr, Mn, Fe, Co,Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Lu, Hf, Ta, W, Re,Os, Ir, Pt, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb,Be, Mg, Ca, Sr, and/or Ba. A combination of these chemical elements withthe gases O₂, N₂, F, Cl, and/or H₂ can also be used as the cathodematerial.

The hollow cathode target magnetic array may have electromagnets ratherthan permanent magnets. In some embodiments, the electromagnets arepositioned around the side walls 1040 of the hollow cathode target.These side electromagnets can balance and unbalance the hollow cathodetarget magnetic array.

In some embodiments, the hollow cathode target, during the sputteringprocess, has a temperature between 20 C and 1000 C. A high targettemperature in the range of 0.5-0.7 of the melting target temperatureincreases the deposition rate since the sputtering yield is a functionof the temperature in this temperature range. In some embodiments, aportion of the target material atoms arriving on the substrate isevaporated from the target surface. In some embodiments, the sputteringyield is increased due to high target temperature.

The high power pulse resonance AC power supply 1020 includes a regulatedvoltage source with variable power feeding 1190, a high power pulsedpower supply with programmable voltage pulse frequency and amplitude1200 and tunable PFN 1240 as shown in FIG. 11 (a). The high power pulsedpower supply with programmable voltage pulse frequency and amplitude1200 has a computer 1230 and controller 1220. A regulated voltage sourcewith variable power feeding 1190 supplies voltage in the range of400-5000 V to the high power pulsed power supply with programmablevoltage pulse frequency and amplitude 1200. The high power pulsed powersupply with programmable voltage pulse frequency and amplitude 1200generates a train of unipolar negative voltage pulses to the tunable PFN1240. The amplitude of the unipolar negative voltage pulses is in therange of 400 to 5000 V, the duration of each of the voltage pulses is inthe range of 1 to 100 μs. The distance between voltages pulses can be inthe range of 0.4 to 1000 μs, thus controlling the frequency to bebetween 0.1 to 400 kHz. In some embodiments, there is a step-uptransformer between the high power pulsed power supply with programmablevoltage pulse frequency and amplitude 1200 and the tunable PFN 1240. Thetunable PFN includes a plurality of specialized variable inductors L1-L4and a plurality of specialized variable capacitors C1-C2 for high powerpulse applications. The value of the inductors and capacitors can becontrolled by computer 1230 and/or controller 1220. In some embodiments,at least one inductor and/or one capacitor are variable and their valuescan be computer controlled. The inductors L1, L2, L3, L4 values can bein the range of 0 to 1000 μH each. Capacitors C1, C2, C3, and C4 havevalues in the range of 0 to 1000 μF each. The high power pulseprogrammable power supply 1200 is connected to controller 1220 and/orcomputer 1230. Controller 1220 and/or computer 1230 control outputvalues and timing of the power supply 1020. Power supply 1020 canoperate as a standalone unit without connection to the controller 1220and/or computer 1230.

A high power pulse resonance AC power supply 1020 shown in FIG. 11(a)includes output current and voltage monitors 1250, 1260, respectively.The current and voltage monitors 1250, 1260 are connected to an arcsuppression circuit 1270. If the current monitor 1250 detects a highcurrent and the voltage monitor 1260 detects a low voltage, the arcsuppression circuit 1270 is activated. It is to be noted that thevoltage monitor 1260 is connected to an output of the tunable PFN. Thearc suppression circuit sends a signal to stop generating incomingvoltage pulses to the tunable PFN 1240 and connects the output of thetunable PFN through switch 1310 to the positive electrical potentialgenerated by power supply 1300 in order to eliminate arcing as shown inFIG. 11 (a). The hollow cathode is shown as a C-shaped structure coupledto the output of the tunable PFN 1240.

The train of unipolar negative voltage pulses from the high power pulseprogrammable power supply 1200 is provided to the tunable PFN 1240.Depending on the amplitude, duration, and frequency of the inputunipolar negative voltage pulses in the train, the output train from thetunable PFN 1240 of the unipolar negative voltage pulses can have adifferent shape and amplitude when compared with input unipolar negativevoltage pulses. In non-resonant mode, in the tunable PFN 1240, the inputtrain of negative unipolar pulses forms one negative voltage pulse withan amplitude equivalent to the amplitude of the negative unipolarvoltage pulses and a duration equivalent to the duration of the inputtrain of unipolar negative voltage pulses. When connected with themagnetically enhanced sputtering source, this voltage pulse can generatea quasi-static pulse DC discharge. In partial resonance mode, in thetunable PFN 1240, the input train of negative unipolar pulses forms onenegative pulse with an amplitude and duration, but with voltageoscillations. The amplitude of these oscillations can be 30-80% of thetotal voltage amplitude. The frequency of the voltage oscillations issubstantially equivalent to the frequency of the input unipolar negativevoltage pulses. This mode of operation is beneficial to maintaining ahigh deposition rate, which is greater than that obtained in fullresonance mode, and a high ionization of sputtered target materialatoms. In resonance mode, the input train of unipolar negative voltagepulses forms asymmetrical AC voltage waveforms with a maximum negativevoltage amplitude that can significantly exceed the voltage amplitude ofthe input unipolar negative voltage pulses. The positive amplitude ofthe AC voltage waveform can reach the absolute value of the negativeamplitude and form a symmetrical AC waveform. In FIG. 11 (b), thepulsing unit generates, during time t1, a train of unipolar negativevoltage pulses with a frequency f1 and amplitude V3 V1 (Please reviewthe voltage, frequency, and time designations regarding at least FIGS.11, 12, 16, and 18 in the description of drawings, detailed descriptionand drawings (I DID).

In FIG. 11 (c), the high power pulse programmable power supply 1190generates, during time t2, a train of unipolar negative voltage pulseswith a frequency f2 and amplitude V3. In this case, the partialresonance mode exists. The amplitude A of the voltage oscillations isabout 30-80% of the voltage amplitude V2. At the end of the pulse, thepositive voltage pulse 1300 can be added by activating a positivevoltage power supply connected to the output of the tunable PFN. If thehigh power pulse programmable power supply 1200 generates unipolarvoltage pulses with a frequency f3 and amplitude V4 during time t3, theresonance mode exists in the PFN 1240. The resonance mode generatesasymmetrical AC voltage waveform. The negative voltage amplitude V5exceeds the amplitude of the input voltage pulses V4 as shown in FIG. 11(d). In some embodiments, the amplitude of the voltage pulses V4 is−1200 V, amplitude of the negative voltage V5 is −1720 V and theamplitude of the positive voltage V6 is +280 V. In some embodiments, theamplitude of the voltage pulses V4 is −1500 V, and amplitude of thenegative voltage V5 is −1720 V. The amplitude of the output positivevoltage V6 is +780 V. Different tunable PFN that can be used to generateasymmetrical AC voltage waveforms are shown in FIGS. 11 (e, f).

In some embodiments, the high power pulse programmable power supplypulsing 1200 can generate a train of unipolar negative voltage pulseswith different amplitudes V7, V8 and frequencies f4, f5 as shown in FIG.12 (a). There is a resonance mode in the tunable PFN 1240 when theoutput negative voltage amplitudes V9, V10 exceed the amplitude of theinput voltage pulses V7, V8 as shown in FIG. 12 (b). During a negativeportion of the asymmetrical AC discharge, a surface of the hollowcathode target 1030 emits secondary electrons due to ion bombardment,and during the positive portion of the asymmetrical AC discharge thehollow cathode 1030 absorbs electrons. The reduced quantity of electronsin the plasma generates a positive plasma potential. This plasmapotential accelerates ions towards the substrate.

During a reactive sputtering process, positive electrical charge isformed on the hollow cathode target surface 1050 due to reactive feedgas interaction with the hollow cathode target surface 1050. Thepositive voltage of the asymmetrical high voltage AC waveform attractselectrons to the hollow cathode target surface. These electronsdischarge a positive charge on top of the cathode target surface 1050and significantly reduce or completely eliminate the probability ofarcing. Since the electrons are absorbed by the hollow cathode targetsurface 1050, it is possible to generate positive space charge in theplasma. The positive space charge provides additional energy to the ionsin the plasma and leads the ions toward the substrate and hollow cathodetarget walls. The positive voltage applied to the cathode target surfacecan attract negative ions that were formed when the negative voltage wasapplied to the target surface and, therefore, reduce substrate ionbombardment.

The tunable PFN 1240 can be connected with a plurality of electricalswitches 1400-1420. The switches 1400, 1410, 1420 are connected toseparate magnetron sputtering sources 1500, 1510, 1520 as shown in FIG.13 (a). For example, during operation, the train 1 of pulses of highvoltage AC waveform is directed to the sputtering source 1500, and thetrain 2 of pulses of high voltage AC waveform is directed to thesputtering source 1510 as shown in FIG. 13 (b). In this approach, smallsize sputtering sources can provide large area sputtering.

The hollow cathode magnetron 1010 from the magnetically and electricallyenhanced HEDP sputtering source 1000 is mounted inside a vacuum chamber4010 to construct the magnetically and electrically enhanced HEDPsputtering apparatus 4000 shown in FIG. 14 (a). The vacuum chamber 4010contains feed gas and plasma, and is coupled to ground. The vacuumchamber 4010 is positioned in fluid communication with a vacuum pump4020, which can evacuate the feed gas from the vacuum chamber 4010.Typical baseline pressure in the vacuum chamber 4010 is in a range of10⁻⁶ to 10⁻⁹ Torr.

A feed gas is introduced into the vacuum chamber 4010 through a gasinlet 4040 from feed gas sources. A mass flow controller 4040 controlsgas flow to the vacuum chamber 4010. In an embodiment, the vacuumchamber 4010 has a plurality of gas inlets and mass flow controllers.The gas flow is in a range of 1 to 1000 SCCM depending on plasmaoperating conditions, pumping speed of a vacuum pump 4030, processconditions, and the like. Typical gas pressure in the vacuum chamber4010 during a sputtering process is in a range of 0.5 to 50 mTorr. Insome embodiments, a plurality of gas inlets and a plurality of mass flowcontrollers sustain a desired gas pressure during the sputteringprocess. The plurality of gas inlets and plurality of mass flowcontrollers may be positioned in the vacuum chamber 401 at differentlocations. The feed gas can be a noble gas, such as Ar, Ne, Kr, Xe; areactive gas, such as N₂, O₂; or any other gas suitable for sputteringor reactive sputtering processes. The feed gas can also be a mixture ofnoble and reactive gases.

The magnetically enhanced HEDP sputtering apparatus 4000 includes asubstrate support 4080 that holds a substrate 4070 or other work piecefor plasma processing. The substrate support 4080 is electricallyconnected to a bias voltage power supply 4090. The bias voltage powersupply 4090 can include a radio frequency (RF) power supply, alternatingcurrent (AC) power supply, very high frequency (VHF) power supply,and/or direct current (DC) power supply. The bias power supply 4090 canoperate in continuous mode or pulsed mode. The bias power supply 4090can be a combination of different power supplies that can providedifferent frequencies. The negative bias voltage on the substrate is ina range of 0 to −2000 V. In some embodiments, the bias power supplygenerates a pulse bias with different voltage pulse frequency,amplitude, and shape as shown in FIG. 13 (b). In some embodiments, thevoltage is a pulse voltage. The negative substrate bias voltage canattract positive ions to the substrate. The substrate support 4008 caninclude a heater 4140 that is connected to a temperature controller4210. The temperature controller 4210 regulates the temperature of thesubstrate 4000. In an embodiment, the temperature controller 4210controls the temperature of the substrate 4070 to be in a range of −100C to (+1000) C.

In some embodiments, the hollow cathode target material is copper andthe substrate is a semiconductor wafer that has at least one via ortrench. The semiconductor wafer diameter is in the range of 25 to 450mm. The depth of the via can be between 100 Å and 400 μm. The via canhave an adhesion layer, barrier layer, and seed layer. Typically, theseed layer is a copper layer. The copper layer can be sputtered with theHEDP magnetron discharge as shown in FIG. 14 (c).

A method of sputtering films, such as hard carbon, includes thefollowing conditions. The feed gas pressure can be in the range of 0.5to 50 mTorr. The substrate bias can be between 0 V and −120 V. Thesubstrate bias voltage can be continuous or pulsed. The frequency of thepulsed bias can be in the range of 1 Hz and 400 kHz. The substrate biascan be generated by RF power supply and matching network. The RFfrequency can be in the range of 500 kHz and 27 MHz. The RF bias can becontinuous or pulsed. In embodiment during the deposition the substratecan have a floating potential. The high power pulse power supply 1200generates a train of negative unipolar voltage pulses with frequency andamplitude that provide a resonance mode in the tunable PFN 1240. In thiscase, tunable PFN 1240 generates the high voltage asymmetrical ACwaveform and, therefore, generates HEDP discharge. The negative ACvoltage can be in the range of −1000 to −10000 V. The duration of thepulse high voltage asymmetrical AC waveforms can be in the range of 1 to20 msec. The substrate temperature during the sputtering process can bein the range of −100 C and +200 C. The hardness of the diamond likecoating formed on the substrate can be in the range of 5 to 70 GPa. Theconcentration of sp3 bonds in the carbon film can be in the range of10-80%. In some embodiments, the feed gas is a noble gas such as Ar, Ne,and Kr. In some embodiments, the feed gas is a mixture of a noble gasand hydrogen. In some embodiments, the feed gas is a mixture of a noblegas and a gas that contains carbon atoms. In some embodiments, the feedgas is a mixture of a noble gas and oxygen in order to sputteroxygenated carbon films CO_(x) for non-volatile memory devices or anyother devices. The oxygen gas flow can be in the range of 1-100 sccm.The discharge current density during the sputtering process can be0.2-20 A/cm². In some embodiments, the amorphous carbon films aresputtered for non-volatile memory semiconductor based devices or for anyother semiconductor based devices.

In some embodiments, the hollow cathode target material is aluminum. Thefeed gas can also be a mixture of argon and oxygen, or argon andnitrogen. The feed gases pass through a gas activation source. In someembodiments, feed gasses pass directly to the vacuum chamber. PFN 1240generates the asymmetrical high voltage AC waveform to provide HEDPmagnetron discharge to sputter hard α-Al₂O₃ coating on the substrate.The substrate temperature during the sputtering process is in the rangeof 350 to 800 C.

HEDP magnetron discharge can be used for sputter etching the substratewith ions from sputtering target material atoms and gas atoms. A methodof sputter etch processing with argon ions and sputtered target materialions uses high negative substrate bias voltage in the range of −900 to−1200 V. The gas pressure can be in the range of 1 to 50 mTorr. Thepulse power supply generates a train of negative unipolar voltage pulseswith frequency and amplitude that provide resonance mode in the tunablePFN 1240. In this case, the PFN 1240 generates the high voltageasymmetrical AC waveform that provides HEDP discharge. For example, asputter etch process can be used to sharpen or form an edge on asubstrate for cutting applications, such as surgical tools, knives, orrazor blade for hair removal applications, or for cleaning a substrateby removing impurities to enhance adhesion. HEDP magnetron dischargealso can be used for ion implantation of ions from sputtered targetmaterial atoms into a substrate. For ion implantation, the negative biasvoltage on the substrate can be in the range −900-15000 V. An ionimplantation example includes the doping of a silicon based device orion implantation to enhance thin film adhesion to the substrate wherethe layer is forming.

In some embodiments, the electrically enhanced HEDP magnetron sputteringsource can be used for chemically enhanced I-PVD deposition (CE-IPVD) ofmetal containing or non-metal films. For example, in order to sputtercarbon films with different concentrations of sp3 bonds in the film, thecathode target may be made from carbon material. The feed gas can be anoble gas and carbon atoms containing gas, such as C₂H₂, CH₄, or anyother gases. The feed gas can also contain H₂. Carbon films on thesubstrate are formed by carbon atoms from the feed gas and from carbonatoms from the cathode target. The carbon films on the substrate areformed by carbon atoms from the feed gas.

The carbon films sputtered with the electrically enhanced HEDP magnetronsputtering source with noble gas, such as Argon, Neon, and the like, orreactive gas, such as Hydrogen, Nitrogen, Oxygen, and the like can beused for hard mask applications in etch processes, such as 3D NAND; forprotectively coating parts, such as bearings, camshafts, gears, fuelinjectors, cutting tools, carbide inserts, drill bits, broaches,reamers, razor blades for surgical applications and hair removal, harddrives, solar panels, optical filters, flat panel displays, thin filmbatteries, batteries for storage, hydrogen fuel cell, cutleries,jewelry, wrist watch cases and parts, coating metal on plastic partssuch as lamps, air vents in cars, aerospace applications, such asturbine blades and jet engine parts, jewelry, plumbing parts, pipes, andtubes; medical implants, such as stents, joints, and the like.

The carbon films sputtered with the electrically enhanced HEDP magnetronsputtering source can be used to sputter thin ta-C and CO_(x) films forcarbon based resistive memory devices.

In some embodiments, the HEDP magnetron discharge with a carbon targetis used to grow carbon nanotubes. In some embodiments, these nanotubesare used to build memory devices.

During the HEDP sputtering process, when the high power pulse asymmetricAC waveform is applied to the magnetically enhanced sputtering source, apulse bias voltage can be applied to the substrate to control ionbombardment of the growing film. The amplitude of the negative voltagecan be in the range of −10 V and −200 V. Trains of asymmetrical ACvoltage waveforms 6020 are shown in FIG. 15 (a). Trains of negativevoltage pulses 6030 applied to the substrate are shown in FIG. 15 (b).In order to control time t1 when bias voltage pulse is applied to thesubstrate, the high power pulse resonance AC power supply and bias powersupply are synchronized. In this case, the controller from the highpower pulse resonance AC power supply sends synchronization pulses thatcorrespond to the trains of asymmetrical AC voltage waveforms to thecontroller from the bias power supply. The bias power supply controllercan set time Δt1 in the range of 0-1000 μs.

In some embodiments, the bias power supply includes an RF power supply.FIG. 15 (c) shows a train of RF pulses 6040 generated by the RF biaspower supply.

The method of generating resonance AC voltage waveforms for themagnetically enhanced sputtering source can also be used to generateresonance AC waveforms for the cathodic arc sources that have widespreadapplications in the coating industry. Resonance AC waveforms, whenconnected with a magnetically enhanced sputtering source, generatevolume discharge. Resonance AC voltage waveforms, when connected with anarc source, generate point arc discharge. DC power supplies generate andsustain continuous arc discharge on an arc evaporation source with acarbon target. The arc current can be in the range of 40-100 A. The arcdischarge voltage can be in the range of 20-120 V. A regulated voltagewith a variable power source feeds the high power pulse programmablepower supply. Specifically, the high power pulse asymmetric AC waveformis generated by having the regulated voltage source with variable powerfeeding a regulated voltage to the high power pulse supply withprogrammable pulse voltage duration and pulse voltage frequencyproducing at its output a train of regulated amplitude unipolar negativevoltage pulses with programmed pulse frequency and duration, andsupplying these pulses to a tunable pulse forming network (PFN)including a plurality of specialized inductors and capacitors designedfor pulse applications connected in a specific configuration coupled toan arc evaporation source. The resonance occurs in the PFN and in thealready existing arc discharge generated by the DC power supply. Byadjusting the pulse voltage amplitude, duration, and frequency of theunipolar negative voltage pulses and tuning the values of the inductorsand capacitors in the PFN coupled to an arc evaporation source, aresonance pulsed asymmetric AC arc discharge can be achieved.

Another method of producing a resonance pulsed asymmetric AC arcdischarge is to have fixed unipolar pulse power supply parameters(amplitude, frequency, and duration) feeding a pulsed forming network,in which the numerical values of the inductors and capacitors, as wellas their configurations are tuned to achieve the desired resonancevalues on the arc evaporation source to form a layer on the substrate.The tuning of the PFN can be performed manually with test equipment,such as an oscilloscope, voltmeter, and current meter or otheranalytical equipment; or electronically with a built-in softwarealgorithm, variable inductors, variable capacitors, and data acquisitioncircuitry. The negative voltage from the pulse asymmetric AC waveformgenerates high density plasma from the evaporated target material atomsbetween the cathode target and the anode of the arc evaporation source.The positive voltage from the pulse asymmetrical AC waveform attractsplasma electrons to the cathode area and generates positive plasmapotential. The positive plasma potential accelerates evaporated targetmaterial ions from the cathode target area towards the substrate thatimprove deposition rate and ion bombardment on the substrate. Thereverse electron current can be up to 50% from the discharge currentduring the negative voltage. In some embodiments, the arc evaporationsource may have one of a rotatable magnetic field, movable magneticfield, or stationary magnetic field. The tunable PFN includes aplurality of capacitors and inductors. The resonance mode associatedwith the tunable PFN is a function of the input unipolar voltage pulseamplitude, duration, and frequency generated by the high power pulsepower supply; inductance, resistance, and capacitance of the arcevaporation source, or any other magnetically enhanced arc evaporationsource; the inductance, capacitance, and resistance of the cablesbetween the tunable PFN and arc evaporation source; and a plasmaimpedance of the arc evaporation source itself as well as the evaporatedmaterial. In the resonance mode, the output negative voltage amplitudeof the high power pulse voltage mode asymmetrical AC waveform on the arcevaporation source exceeds the negative voltage amplitude of the inputunipolar voltage pulses into the tunable PFN by 1.1-5 times. Theunipolar negative high power voltage output can be in the range of400V-5000V. In the resonance mode, the absolute value of the negativevoltage amplitude of the asymmetrical AC waveform can be in the range of750-5000 V. In the resonance mode, the output positive voltage amplitudeof the asymmetrical AC waveform can be in the range of 100-2500 V.

In the resonance mode, the negative voltage amplitude of the output ACwaveform can reach a maximum absolute value at which point a furtherincrease of the input voltage to the tunable PFN will not result in avoltage amplitude increase, but rather an increase in duration of thenegative pulse in the asymmetric AC waveform. In some embodiments, thefrequency of the unipolar voltage pulses is in the range of 1 kHz and 10kHz. In some embodiments, the duration of the unipolar voltage pulses isin the range of 3-20 μs. Asymmetrical AC voltage waveforms significantlyinfluence the size on of the cathode arc spot and velocity. In someembodiments, generation of the resonance AC voltage waveforms reduce theformation of macro particles from evaporated cathode target material.

In an embodiment, a high power pulse resonance AC power supply 7000, ascompared with the high power pulse resonance AC power supply 1020 shownin FIG. 10 (g), includes a high frequency high power pulsed power supply7010 with a programmable voltage pulse frequency and amplitude as shownin FIG. 16 (a). The high frequency high power pulsed power supply 7010generates pulse negative, unipolar oscillatory voltage waveforms with afrequency in the range of 100 KHz to 5 MHz and a duration t1 in a rangeof 5 μs to 20 μs. The absolute value of the voltage of these waveformsis in a range of 500 V to 5000 V. The frequency of these pulses withnegative unipolar voltage waveforms is in a range of 5 Hz to 200 KHz.

Pulse negative unipolar oscillatory voltage waveforms 8000 are shown inFIG. 16 (b). The tunable PFN 1240, which is in resonance mode for thesepulses, generates a high power resonance asymmetrical AC waveform. Theresonance mode can be achieved by adjusting the values of inductors L1,L2, L3, and L4 and by adjusting the values of capacitors C1 and C2 for aparticular shape of the pulse negative unipolar oscillatory voltagewaveforms, their frequency, type of process gas, target material, andmagnetic field strength of the hollow cathode sputtering source 7020.The resonance mode is defined by conditions when the adjustment of thefrequency and amplitude of the plurality of negative unipolaroscillatory voltage waveforms 800 generate the plurality of asymmetricalAC voltage waveforms 8010, 8020 with positive V+ and negative V−voltages shown in FIGS. 16 (b, c). Further increase of the oscillatoryvoltage waveform amplitude causes an increase in the value of thepositive portion of the AC voltage waveform. By adjusting time t1, timet2, or both time t1 and time t2, double negative peak asymmetrical ACvoltage waveforms 8020 can be achieved as shown in FIG. 16 (d).

In an embodiment, a magnetically and electrically enhanced HEDPsputtering source 1000 shown in FIG. 10 (g) has a hollow cathode target1030 that includes two parts as shown in FIG. 17 (a) and FIG. 17 (b).FIG. 17 (a) shows the hollow cathode target 1030 that includes pieces7030 and 7050. These two pieces are attached to a copper baking plate bya clamp 7040. FIG. 17 (b) shows the hollow cathode target that includepieces 7070 and 7080. These two pieces are bonded to the copper bakingplate 7060.

In an embodiment, the hollow cathode target 1030 includes two pieces7100 and 7090 as shown in FIG. 18 (a). The piece 7090 has magnetic fieldlines 7150 and the piece 7100 has magnetic field lines 7140. Each ofthese pieces is connected to different high power pulse resonance ACpower supplies 7110 and 7120. The block diagram of these high powerpulse resonance AC power supplies is shown in FIG. 16 (a). The highpower pulse resonance AC power supplies 7110 and 7120 generate ACvoltage waveforms 7150 and 7160 shown in FIGS. 18 (a) and 18 (b). A timeshift between negative voltage peaks 7170 and 7180 is controlled throughcontroller 7190. In an embodiment, the power supply 7110 sends a synchropulse to power supply 7120 to initiate the start of power supply 7120.In an embodiment, the power supply 7120 sends a synchro pulse to powersupply 7110 to initiate the start of power supply 7110. The time shiftinfluences electron energy and, therefore, a degree of ionization ofsputtered material atoms. In an embodiment, the time shift is in a rangeof 10 to 1000 microseconds.

In an embodiment, a magnetically enhanced HEDP sputtering source that isshown in FIG. 10 (g) includes an additional magnetic assembly positionedadjacent to the side walls 1040 as shown in FIG. 10 (h). The magneticassembly may have permanent magnets or electromagnets or a combinationof permanent magnets and electromagnetics.

In an embodiment, a high power pulse resonance AC power supply 8100includes an AC power supply 8110 and PFN 8120 as shown in FIG. 19. Highpower AC power supply 8110 can generate different AC voltage waveformsat the output as shown in FIGS. 20 (a, b, c, d, e, f). The frequency ofthese voltage waveforms can be in the range of 3 KHz to 100 KHz. Thepeak voltage amplitude can be in the range of 100 V to 1000 V. The PFNincludes a step-up transformer 8130, a diode bridge 8140, a plurality ofinductors 8150, 8160, 8170, 8180, and a plurality of capacitors 8190 and8200. This PFN converts AC voltage waveforms to an asymmetrical complexAC voltage waveform during the resonance mode as shown in FIG. 19. ACvoltage waveforms and frequencies that correspond to this particular ACvoltage waveform are associated with specific values of inductors 8150,8160, 8170, 8180 and capacitors 8190, 8200 in order to generate theresonance mode and form, at the output, the asymmetrical AC voltagewaveform. In an embodiment, the PFN does not have a diode bridge.

In an embodiment, the high power pulse resonance AC power supply can beconnected to the HEDP magnetron sputtering source and RF power supply.The frequency of the RF power supply can be in the range of 500 KHz to30 MHz. The RF power supply can operate in continuous mode or pulsedmode. In an embodiment, the RF power supply turns on before on the highpower pulse resonance AC power supply turns on in order to providestable plasma ignition for plasma that will be generated with the highpower pulse resonance AC power supply. The RF power supply can be turnedoff after the high density plasma is generated. In an embodiment, the RFpower supply operates in continuous mode together with the high powerpulse resonance AC power supply. This operation reduces parasitic arcsduring the reactive sputtering process. This operation is beneficial forsputtering ceramic target materials and target materials with lowelectrical conductivity such as those containing B, Si, and the like.

The output voltage waveforms from the high power pulse resonance ACpower supply are shown in FIG. 22 (a, b). The second negative peak 8120can be generated by controlling parameters of the PFN, such asinductors, capacitors and the transformer (if applicable) as shown inFIG. 22 (a). The peak 8120 has a significant influence on theprobability of generating arcs during reactive sputtering. The plasmathat is generated during this peak helps to ignite high density plasmaduring the first negative peak 8110. The second peak 8120 may betriangular, sinusoidal or rectangular in shape. The rectangular shape ofthe second negative peak 8140 is shown in FIG. 22 (b). The value andduration of the peak 8120 helps to control the energy of ions coming tothe substrate. The duration t_(s) can be in the range of 2 μs to 50 μs.The amplitude V_(s) can be in the range of 200 V to 1000 V. The greaterthe amplitude and/or duration of the second peak is, the less the ionenergy will be. This arrangement is of particular importance forsputtering ta-C films when high ion energy can affect film structure.

In an embodiment, the HEDP sputtering source has a ring-shaped hollowcathode target as shown in FIG. 23. The HEDP sputtering source includesan anode, ring-shaped hollow cathode target, and PFN 1240. The magnets3001, 3002 generate a magnetic field 3003 inside the ring-shaped hollowcathode target.

FIG. 24 shows a segmented HEDP sputtering source. The segmented HEDPsputtering source includes a ring-shaped hollow cathode target 2243 anda hollow cathode target 2242. A plurality of magnets 2241 generates amagnetic field 3003 inside the ring-shaped hollow cathode target 2243.The ring-shaped hollow cathode target 2243 is connected to the PFN 1240.A plurality of magnets 2244, 2245 generates a magnetic field 3004. Ahollow cathode target 2242 is connected to the PFN 2240.

FIG. 25 (a) shows a tunable PFN 8000 that can be connected to theV-shaped HEDP magnetron shown in FIG. 25 (b). The magnets 8002 generatea magnetic field 8003 near the cathode target 8001.

The tunable PFN shown in FIG. 25 (a) is turned such that the HEDPmagnetron sputtering source operates in ARC mode. The typical outputvoltage and current waveforms are shown in FIGS. 26 (a, b).

In an embodiment, the vacuum process chamber 8207, as shown in FIG. 27,includes a magnetron sputtering source 8208, 8209, cathodic arcdeposition source 8210, and HEDP magnetron sputtering source 8211. TheHEDP magnetron sputtering source 8211 can operate in sputtering mode orARC mode.

FIG. 28 shows an illustrative view of the hollow cathode target fromHEDP magnetron sputtering source. The hollow cathode target includes aring shaped target 9504 and flat disc 9501. The flat disc is positionedinside a copper water cooled jacket 9500. The gas distribution system9502 is positioned on top of the ring shape target 9504. The gasdistribution system 9502 has a plurality of openings 9510. Theseopenings provide uniform gas distribution. The gas distribution system9502 is connected to a gas source through tube 9503.

FIG. 29 shows an illustrative diagram of a substrate bias power supply.The substrate bias power supply includes two charging units. The lowvoltage unit 9505 can provide voltage in a range of 0-200 V. The lowvoltage unit 9505 can provide voltage in a range of 200-1500 V.Depending on process conditions, controller 9508 can send a signal tothe switch 9507 that determines the charging units that will chargecapacitor bank C20 from the power supply 9509.

In an embodiment, the HEDP magnetron sputtering source 1010 with carbontarget 1040 can be used for sputtering hydrogen free DLC (diamond likecoatings) films as shown in FIG. 14 (a). The programmable duration ofthe AC pulse bursts can be in the range of 0.5-20 ms. The frequency ofthe programmable AC pulse bursts can be in the range of 1 Hz-100 Hz. Thefrequency of the pulsed AC waveform inside the programmable pulse burstscan be programmed in the range of 10 kHz-60 kHz with a single frequencyor mixed frequency. The average power during the deposition process canbe in the range of 1-5 kW. The target area can be in the range of 50-500cm². The Argon gas pressure can be in the range of 1-20 mTorr. The filmhardness of the hydrogen free DLC film can be in the range of 20-35 GPa.

In an embodiment, the HEDP magnetron sputtering source 1010 with carbontarget 1040 can be used for sputtering hydrogenated DLC (diamond likecoatings) films as shown in FIG. 14 (a). The programmable duration ofthe AC pulse bursts can be in the range of 0.5-10 ms. The frequency ofthe programmable AC pulse bursts can be in the range of 10 Hz-600 Hz.The frequency of the pulsed AC waveform inside the programmable pulsebursts can be programmed in the range of 10 kHz-60 kHz with a singlefrequency or mixed frequency. The average power during the depositioncan be in the range of 1-5 kW. The target area can be in the range of50-500 cm². The Argon gas pressure can be in the range of 1-20 mTorr.The carbon containing gas flow can be in the range of 10 SCCM and 200SCCM. In embodiment the gas was acetylene. The film hardness of thehydrogenated DLC film can be in the range of 15-30 GPa.

In an embodiment, the HEDP magnetron sputtering source 1010 with metaltarget 1040 can be used for sputtering hydrogenated metal DLC (diamondlike coatings) films as shown in FIG. 14 (a). The target material can beW, Ti, Cr, Si, Ta, or any other metal. The programmable duration of theAC pulse bursts can be in the range of 0.5-10 ms. The frequency of theprogrammable AC pulse bursts can be in the range of 100 Hz-800 Hz. Thefrequency of the pulsed AC waveform inside the programmable pulse burstscan be programmed in the range of 10 kHz-60 kHz with a single frequencyor mixed frequency. The Argon gas pressure can be in the range of 1-20mTorr. The average power during the deposition can be in the range of1-5 kW. The target area can be in the range of 50-500 cm². The carboncontaining gas flow can be in the range of 10 SCCM and 200 SCCM. In anembodiment, the gas can be acetylene. The film hardness of thehydrogenated DLC film can be in the range of 15-30 GPa.

In an embodiment, the HEDP magnetron sputtering source 1010 with metaltarget 1040 can be used for sputtering metal nitride films as shown inFIG. 14 (a). The target material can be W, Ti, Cr, Si, Al, TiAl, Ta, orany other metal. The programmable duration of the AC pulse bursts can bein the range of 0.5-2 ms. The frequency of the programmable AC pulsebursts can be in the range of 100 Hz-800 Hz. The frequency of the pulsedAC waveform inside the programmable pulse bursts can be programmed inthe range of 10 kHz-60 kHz with a single frequency or mixed frequency.The average power during the deposition can be in the range of 1-5 kW.The Argon gas pressure can be in the range of 1-20 mTorr. The targetarea can be in the range of 50-500 cm². The Nitrogen gas flow can be inthe range of 10 SCCM and 200 SCCM. The film hardness of the hydrogenatedDLC film can be in the range of 15-35 GPa.

In an embodiment, the HEDP magnetron sputtering source 1010 with metaltarget 1040 can be used for sputtering metal films as shown in FIG. 14(a). The target material can be W, Ti, Cr, Si, Al, TiAl, Ta, or anyother metals. The programmable duration of the AC pulse bursts can be inthe range of 0.5-2 ms. The frequency of the programmable AC pulse burstscan be in the range of 100 Hz-800 Hz. The frequency of the pulsed ACwaveform inside the programmable pulse bursts can be programmed in therange of 10 kHz-60 kHz with a single frequency or mixed frequency. Theaverage power during the deposition can be in the range of 1-5 kW. TheArgon gas pressure can be in the range of 1-20 mTorr. The target areacan be in the range of 50-500 cm². The deposition rate can be in therange of 5-60 microns per hour depends on the distance between thetarget and the substrate.

In an embodiment, the HEDP magnetron sputtering source 1010 with metaltarget 1040 can be used for sputtering metal oxide films as shown inFIG. 14 (a). The target material can be W, Ti, Cr, Si, Al, TiAl, Ta, orany other metal. The programmable duration of the AC pulse bursts can bein the range of 0.5-2 ms. The frequency of the programmable AC pulsebursts can be in the range of 100 Hz-800 Hz. The frequency of the pulsedAC waveform inside the programmable pulse bursts can be programmed inthe range of 10 kHz-60 kHz with a single frequency or mixed frequency.The average power during the deposition can be in the range of 1-5 kW.The target area can be in the range of 50-500 cm². The Argon gaspressure can be in the range of 1-20 mTorr. The Oxygen gas flow can bein the range of 10 SCCM and 200 SCCM.

In an embodiment, the HEDP magnetron sputtering source 1010 with target1040 can be used for sputter etch process of the substrate as shown inFIG. 14 (a). The target material can be W, Ti, Cr, Si, Ta, or any othermetal. The programmable duration of the AC pulse bursts can be in therange of 0.5-2 ms. The frequency of the programmable AC pulse bursts canbe in the range of 100 Hz-800 Hz. The frequency of the pulsed ACwaveform inside the programmable pulse bursts can be programmed in therange of 10 kHz-60 kHz with a single frequency or mixed frequency. TheArgon gas pressure can be in the range of 1-20 mTorr. The average powerduring the deposition can be in the range of 1-5 kW. The target area canbe in the range of 50-500 cm². The substrate bias can be in the range of−(500-1500) V.

In an embodiment, prior to sputtering hydrogenated DLC film on top ofthe steel substrate, the substrate surface can be cleaned with a sputteretch process described above.

The illustrations of embodiments described herein are intended toprovide a general understanding of the structure of various embodiments,and they are not intended to serve as a complete description of all theelements and features of apparatus and systems that might make use ofthe structures described herein. Many other embodiments will be apparentto those of skill in the art upon reviewing the above description. Otherembodiments are utilized and derived therefrom, such that structural andlogical substitutions and changes are made without departing from thescope of this disclosure. Figures are also merely representational andare not drawn to scale. Certain proportions thereof are exaggerated,while others are decreased. Accordingly, the specification and drawingsare to be regarded in an illustrative rather than a restrictive sense.

Such embodiments are referred to herein, individually and/orcollectively, by the term “embodiment” merely for convenience andwithout intending to voluntarily limit the scope of this application toany single embodiment or inventive concept if more than one is in factshown. Thus, although specific embodiments have been illustrated anddescribed herein, it should be appreciated that any arrangementcalculated to achieve the same purpose are substituted for the specificembodiments shown. This disclosure is intended to cover any and alladaptations or variations of various embodiments. Combinations of theabove embodiments, and other embodiments not specifically describedherein, will be apparent to those of skill in the art upon reviewing theabove description.

In the foregoing description of the embodiments, various features aregrouped together in a single embodiment for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting that the claimed embodiments have more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle embodiment. Thus, the following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate example embodiment.

The abstract is provided to comply with 37 C.F.R. § 1.72(b), whichrequires an abstract that will allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle embodiment. Thus, the following claims are hereby incorporatedinto the Detailed Description, with each claim standing on its own asseparately claimed subject matter.

Although specific example embodiments have been described, it will beevident that various modifications and changes are made to theseembodiments without departing from the broader scope of the inventivesubject matter described herein. Accordingly, the specification anddrawings are to be regarded in an illustrative rather than a restrictivesense. The accompanying drawings that form a part hereof, show by way ofillustration, and without limitation, specific embodiments in which thesubject matter are practiced. The embodiments illustrated are describedin sufficient detail to enable those skilled in the art to practice theteachings herein. Other embodiments are utilized and derived therefrom,such that structural and logical substitutions and changes are madewithout departing from the scope of this disclosure. This DetailedDescription, therefore, is not to be taken in a limiting sense, and thescope of various embodiments is defined only by the appended claims,along with the full range of equivalents to which such claims areentitled.

Given the teachings provided herein, one of ordinary skill in the artwill be able to contemplate other implementations and applications ofthe techniques of the disclosed embodiments. Although illustrativeembodiments have been described herein with reference to theaccompanying drawings, it is to be understood that these embodiments arenot limited to the disclosed embodiments, and that various other changesand modifications are made therein by one skilled in the art withoutdeparting from the scope of the appended claims.

What is claimed is:
 1. An electrically and magnetically enhanced ionizedphysical vapor deposition (I-PVD) method of sputtering a layer on asubstrate using a magnetron, the method comprising: positioning themagnetron in a vacuum with an anode, a first cathode target, acylindrical cathode target, a magnet assembly, the substrate, and a feedgas; applying a plurality of unipolar negative direct current (DC)voltage pulses from a pulse power supply to a first pulse formingnetwork (PFN), the first PFN comprising at least one inductor and atleast one capacitor; adjusting at least one of an amplitude, pulseduration, and frequency associated with the plurality of unipolarnegative DC voltage pulses and adjusting a value of at least one of theat least one inductor and the at least one capacitor, thereby causing aresonance mode associated with the first PFN, the first PFN convertingthe unipolar negative DC voltage pulses to a first asymmetricalternating current (AC) signal that generates a first asymmetric ACdischarge on the magnetron with pulse current densities in a range ofabout 0.1 to 20 A/cm², the first asymmetric AC signal operativelycoupled to the first cathode target, the first asymmetric AC signalcomprising a first negative voltage and a first positive voltagefollowed by a second negative voltage, the second negative voltagegenerating plasma for use during a subsequent negative voltageassociated with the first asymmetric AC signal; coupling a second PFNoperatively to the cylindrical cathode target, the cylindrical cathodetarget associated with a second magnetron comprising a second unbalancedmagnetic field, the second PFN generating a second asymmetric AC signaland a second asymmetric AC discharge on the cylindrical cathode target,the second asymmetric AC signal comprising a first negative voltage anda first positive voltage followed by a second negative voltage, thesecond negative voltage generating plasma for use during a subsequentnegative voltage associated with the second asymmetric AC signal; anddisposing a time shift between negative voltage peaks associated with atleast one of the first asymmetric AC discharge and the second asymmetricAC discharge, the time shift being selected to increase ionization ofsputtered target material on the substrate during sputtering.
 2. Themethod, as defined by claim 1, further comprising coupling a substratebias voltage to a substrate holder, the substrate bias voltagecomprising a range of −10 V to −2000 V.
 3. The method, as defined byclaim 1, wherein the feed gas comprises a noble gas, the noble gascomprising at least one of argon, xenon, neon, or krypton.
 4. Themethod, as defined by claim 1, wherein the feed gas comprises a mixtureof a noble gas and a reactive gas.
 5. The method, as defined by claim 1,wherein the feed gas comprises a mixture of a noble gas and a gas thatcomprises atoms associated with at least one of the flat cathode target,or the cylindrical cathode target.
 6. The method, as defined by claim 1,further comprising rotating at least one of the first cathode target, orthe cylindrical cathode target with a speed in a range of 10 to 100revolutions per minute.
 7. The method, as defined by claim 1, wherein atleast one of the first PFN, or the second PFN comprises at least one ofselectable voltage, power, or frequency.
 8. The method, as defined byclaim 1, wherein negative voltage peaks associated with the firstasymmetric AC discharge and the second asymmetric AC discharge aresubstantially simultaneous.
 9. The method, as defined by claim 1,further comprising providing a pulse by the first PFN to the second PFNthat initiates a start of the second PFN.
 10. The method, as defined byclaim 1, further comprising providing a pulse by the second PFN to thefirst PFN that initiates a start of the first PFN.
 11. An electricallyand magnetically enhanced ionized physical vapor deposition (I-PVD)sputtering apparatus that deposits a layer on a substrate using amagnetron, the apparatus comprising: a magnetron, the magnetronpositioned in a vacuum with an anode, a first cathode target, acylindrical cathode target, a magnetic assembly, the substrate, and afeed gas; a first pulse forming network (PFN) receiving a plurality ofunipolar negative direct current (DC) voltage pulses from a pulse powersupply, the first PFN comprising at least one inductor and at least onecapacitor, at least one of an amplitude, pulse duration, and frequencyassociated with the plurality of unipolar negative DC voltage pulsesbeing adjusted and a value of at least one of the at least one inductorand the at least one capacitor being adjusted, thereby causing aresonance mode associated with the first PFN, the first PFN convertingthe unipolar negative DC voltage pulses to a first asymmetricalternating current (AC) signal that generates a first asymmetric ACdischarge on the magnetron with pulse current densities in a range ofabout 0.1 to 20 A/cm², the first asymmetric AC signal operativelycoupled to the first cathode target, the first asymmetric AC signalcomprising a first negative voltage and a first positive voltagefollowed by a second negative voltage, the second negative voltagegenerating plasma for use during a subsequent negative voltageassociated with the first asymmetric AC signal; and a second PFNoperatively coupled to the cylindrical cathode target, the second PFNgenerating a second asymmetric AC signal and a second asymmetric ACdischarge on the cylindrical cathode target, the second asymmetric ACsignal comprising a first negative voltage and a first positive voltagefollowed by a second negative voltage, the second negative voltagegenerating plasma for use during a subsequent negative voltageassociated with the second asymmetric AC signal, wherein a time shift isdisposed between negative voltage peaks associated with the firstasymmetric AC discharge and the second asymmetric AC discharge, the timeshift being selected to increase ionization of sputtered target materialon the substrate during sputtering.
 12. The apparatus, as defined byclaim 11, further comprising a substrate bias power supply coupled to asubstrate holder, the substrate bias power supply providing a biasvoltage on the substrate in a range of −10 to −2000 V.
 13. Theapparatus, as defined by claim 11, wherein the feed gas comprises anoble gas, the noble gas comprising at least one of argon, xenon, neon,or krypton.
 14. The apparatus, as defined by claim 11, wherein the feedgas comprises a mixture of a noble gas and a reactive gas.
 15. Theapparatus, as defined by claim 11, wherein the feed gas comprises amixture of a noble gas and a gas that comprises atoms associated with atleast one of the first cathode target, or the cylindrical cathodetarget.
 16. The apparatus, as defined by claim 11, wherein at least oneof the first cathode target, or the cylindrical cathode target rotateswith a speed in a range of 10 to 100 revolutions per minute.
 17. Theapparatus, as defined by claim 11, wherein at least one of the firstPFN, or the second PFN comprises at least one of selectable voltage,power, or frequency.
 18. The apparatus, as defined by claim 11, whereinnegative voltage peaks associated with the first asymmetric AC dischargeand the second asymmetric AC discharge are substantially simultaneous.19. The apparatus, as defined by claim 11, wherein the first PFNprovides a pulse to the second PFN that initiates a start of the secondPFN.
 20. The apparatus, as defined by claim 11, wherein the second PFNprovides a pulse to the first PFN that initiates a start of the firstPFN.
 21. The method, as defined by claim 1, wherein the at least one ofthe cathode targets comprises at least one of the following elements: B,C, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, Te, I, Tl, Pb, Bi, Sc, Ti,Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Lu,Hf, Ta, W, Re, Os, Ir, Pt, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy,Ho, Er, Tm, Yb, Be, Mg, Ca, Sr, or Ba.
 22. The method, as defined byclaim 1, wherein the substrate comprises at least a portion of at leastone of a bearing, a camshaft, a gear, a fuel injector, a cutting tool, acarbide insert, a drill bit, a broach, a reamer, a razor blade forsurgical applications and hair removal, a hard drive, a solar panel, anoptical filter, a flat panel display, a thin film battery, a battery forstorage, a hydrogen fuel cell, a turbine blade, a jet engine part,jewelry, a plumbing part, a pipe, a tube, a medical implant, a medicalstent, an artificial joint, a semiconductor wafer, a film used tomanufacture an electronic memory device, or a diamond like coating hardmask.
 23. The apparatus, as defined by claim 11, wherein at least one ofthe cathode targets comprises at least one of the following elements: B,C, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, Te, I, Tl, Pb, Bi, Sc, Ti,Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Lu,Hf, Ta, W, Re, Os, Ir, Pt, Au, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy,Ho, Er, Tm, Yb, Be, Mg, Ca, Sr, or Ba.
 24. The apparatus, as defined byclaim 11, wherein the substrate comprises at least a portion of at leastone of a bearing, a camshaft, a gear, a fuel injector, a cutting tool, acarbide insert, a drill bit, a broach, a reamer, a razor blade forsurgical applications and hair removal, a hard drive, a solar panel, anoptical filter, a flat panel display, a thin film battery, a battery forstorage, a hydrogen fuel cell, a turbine blade, a jet engine part,jewelry, a plumbing part, a pipe, a tube, a medical implant, a medicalstent, an artificial joint, a semiconductor wafer, a film used tomanufacture an electronic memory device, or a diamond like coating hardmask.